Having doubts?   Purge them, buy this card.  Support this company.
Just bought 570 GTX SC.   Two friends of mine have them and are enjoying their cool and quiet beastly cards as well.  As you may have seen here or on newegg.com, temperatures get mentioned alot.  I don't have some super ultra deluxe case, it's decent.   I'll admit, I had my doubts and concerns regarding the temperatures because of the nay sayers.
 
I can easily max CoD Black Ops, BF Bad Company 2, Dragon Age, Starcraft, (minecraft, lulz) Mass Effect in 19whatever x 1080 on a 24 inch (easily) and not push temps past the 50s using the fans at 60%.  And I remind you this is a superclocked we're talking about not a stock 570 GTX.
Not sure what dangerous circumstances these people are putting their cards under to achieve these legendary high 60-70-80 temps even with the fans on auto.  My XFX 285 GTX found it's way into the high 70s easily.  Card was garbage, and the company wanted to give me a run around on the RMA, did the same thing to my neighbor (Three times..).  XFX = Horrible customer service, which is why they aren't making GeForce cards anymore.  EVGA customer service is phenominal.   I've also heard the 500 series runs cooler then the 400 series.  Maybe so, but I know two others with 400 series EVGA cards that also never get out of the 50s, sometimes low 60s.
 
Some things you want to take into consideration would be these:
 
1) Heat of your PC can and will be affected by the temperature of your home, room, etc.  Don't go and think you are going to tuck your case into a corner covered in laundry with the house being 90+ degrees and pull off 50 degree temps running graphically demanding games in max while pushing two monitors with a basic case, or even a semi good one.  Not happening.
 
2) Make sure you don't have a space heater or blow drier or furnace aimed directly into the side of your case.  This I suspect is the leading cause of your cards running as hot as they are. 
3) If you were ironing your clothes across the top of your 570 SC, consider that may also be a cause of your high temperatures.
 
No but seriously, I know it can be a troubling thing to have high card temps, not trying to poke fun at your heating misfortune even if you insist on frying eggs and bacon on the back of your 570.  Idling at 32c right now, and I just finished playing black ops not that long ago.  Yes my home's temperature is about 74 degrees.   Make sure there is ample ventilation and space for your card to breathe, move it away from any possible heat source, perhaps even move it closer to a central air vent.  (Assuming the heating isn't on.)  Mine is across the room hoowever. 
Don't tuck the back of your computer directly up to the wall or surround it's vents with items that might obstruct air flow.
 
This card is amazing.  Fans even at 60% run very quietly.  It's going to eat this years DX11 games handily.  First up, Dragon Age II and Shogun2: Total War (Yes both DX11), then Mass Effect 3 and Elder Scrolls: Skyrim this fall. 
 
EVGA, I am a first time customer... and I salute you. 
 
Templar out.

Well the temperatures of the card will depend of the amb temp so no surprise, but if your card is never reaching 60, under load (hard to belive), well good for you but normal temps under load of 570/580 are near 80C, and for 470/480 near 90 so no worries if it arround these temps.
 
The only problem of the 470/480 is that at these temps the fan is a little noise.

Get a EVGA Superclocked GTX460 External Exhaust, then complain to me about noise.
 
My Superclocked 570 has been a whisper in comparison, even under full load.

I've got an Antec 1200 and turn up the front fans to max when playing BFBC2.  Temps reach mid 80s with all settings @ High, 4xAA, 4xAS, Bloom=False, HBAO=True, at a resolution of 1680x1050.  Mind you, the room my PC is in is about 70 degrees give or take 10 the past week or so.  I play for hours with no performance issues.  The current framerate is almost double what I was getting with my EVGA GTX260 SC card and settings were medium and no AA/AS using that card. I do have a relatively large fan that I run at the lowest setting (too loud if any higher).  An air conditioner is currently being squeezed into the budget this month.
 
Right now, it's idling @ 49 degrees, fan @ 50%.  AMD Phenom II X4 965 BE (140W version) currently @ 43 degrees.  About a month ago I installed the Coolermaster Hyper 212+ and it's actually running about 10-15 degrees cooler on average. (Room temp was quite a bit cooler a month ago...I'd hate to see what I'd be cooking the CPU at if I'd left the stock cooler on it.)
 
I was using a second 17" monitor, but for now, I'll just make due with the main 22", as temps rise about 7-10 degrees with both screens on.  When the AC is up and running, the 17" goes back on.
 
I've had the 570 since the 26th of last month, and it hasn't stopped kicking ass since it was installed. (67 hours of 80+ temps in BC2 alone the past two weeks). 
 
Long story short, (my) 570 SC runs relatively hot (90 is max safe I've read), but so far I wouldn't classify it as an issue.  If it does happen to fry before I install the AC, I'll post it here.
 
 

105 sounds a lot better than 90 for my situation.   I actually double checked nvidia's site and I was off a bit...they state 97 degrees...but I'll take the card manufacturer's specs.  Looks like I should be fine without AC for another week or so.

Couple of notes from a GTX 570 SC owner:
Mine came with the high flow bracket already installed, which I am assuming is now the norm for these cards. Upon first installation, the card would touch 80c under heavy use. After turning on fan profiles in Precision, they never go above 70c. I can certainly hear the fan under heavy load, but I would hardly call it loud. Granted, my case might be part of the reason for that.
 
It's in an Antec P182, middle hard drive cage removed with 120mm fan blowing in on the card.
 
(Side note: This is an awesome case, but it wasn't designed for the AX750 behemoth in the lower PSU chamber. Had to move the 120mm fan from the bottom chamber to blowing on the GPU. I think we're gonna need a bigger boat.)

I just set up a linear scale, pretty simple. You will want to have Precision start with Windows, if Precision is closed the fan control will default to bios control.