i just gave away my 8800gt to my buddy while he was here, and now need a video card setup.  i want ati, i have had nvidia for a long time, and seen what picture quality ati can produce, and would like to give them a try.  so, the question is, will the 4870 be that much better than the 3870?  or will it be an upset like 9000 series over the 8000 series cards?  if not, i will buy a pair of 3870s when i get to san diego, or a pair of 4000 cards if they really are that "good".  also, i hope the 9850 phenom is out then, and some better ram and mobo and i will be set!!!

Well all know in 2 months.......

I've heard rumors that its going to be immaculate. Move over 9800GX2, these ungodly GPUs have to be forged in a volcano and mythical griffans have to swoop down to fetch these cards. At the end of its production line, to top it off there sprinkled with god dust to give them there extra kick.
 
It's really like asking, "When I use the toilet tomorrow, how big is my Poo going to be?"    
 
The Answer is... No one knows until it's released.
 
Theres very little information thats available on these cards so your guess is as good as everyone elses. But so far I think ATI is on the right track, and I like the idea of value for money, whether its single or multi GPU setup, which really speaks to the middle segment and each product shows a bit of growth potential with hybrid CF or crossfire.

Honestly I dont think the 4870 will beat the 9800gtx or 4870x2 be able to beat the 9800gx2 by much either...
 
Ati dont have a single card than can get anywhere near a 8800gtx/9800gtx and 2 to 3 months is a long time, by then Nvidia could have something new out again...
 
Ati are giving very good bang for buck, but they are not competing at the high end single/ dual card stage...
 
They are making things very complicated for people ie 2 x HD3870 on a crossfire board to compete with one 9800gtx

short answer: yes it will.
Based on the rumoured specs it'll have more of everything and faster memory GDDR5.
one 4870 is rumoured to be pretty close to a pair of 3870s, so 4870x2 should be even with 9800gx2 if not better

I agree with Kari. The short answer is that the 4800s will perform better than the 3800s. The question that is unknown is: By how much? I have a 3870 on order at the memont. Its purpose is to get my new build running at fairly decent rates until the 4800s come out. At that time, I'll make a choice as to buying a pair of 4800s or buy another 3870, depending on the performance of the 4800. If I replace the 3870, it won't go to waste, but will used to replace the 7800 GTX that's currently in my business computer, so the purchase won't be wasted.

After the Nvidia 9x fiasco I'm quite sure ATI would do its homework.

 
Yeah, and ATI had its own fiasco last year with the 2900, so it has even more reason not to repeat its mistakes.

I personally would also agree with Kari. I have heard similar rumors saying it would have great improvement over current gen. I think it's well worth waiting. Even if it turns out to be not what we are hoping for, I'm sure there will be much better options than 2x 3870 by that time (money-wise too), so buy something for now and hold until then.

@ Sailor.  Eggjactly!!

Depends
Depends on weather you had white castle jelepeno burgers or a huge bean burritto

Well, it SHOULD beat out anything out today.  Now, as for what NVidia will come out with and how that performs compared to it, who knows.

You want a rumor? Heres one that may come true. 4870 10% faster than the Ultra

Anyone who bashes the 2900 series should try running a 2900XT with cat. version 8.3. then make an educated opinion. The series has come into its own. Granted,the card was and is overpriced. But those of us who did take the plunge and buy one are not regretting it one bit. the 2900xt will beat a 3870 in just about every single benchmark. Again, I understand the price to performance ratios are not in favor of the 2900 series but at least we can run any game out there with all the settings jacked up. And DX10 performance took an impressive leap ahead with the 8.3 cats.I'm looking forward to see how the tech grows because the architecture is remaining close to the same as the 2900 series which means the 2900 series will continue to grow in performance as drivers are released for the 4000 series and beyond.

 
If that rumor comes true, I can definitely see a couple 4870s in my new build. But we have to wait and see if the rumor is true.  
 
Wouldn't it be nice if the rumor was false but in the other direction, like the 4870 being 15% faster than an Ultra?    

 
My earlier comment toward the 2900 being a fiasco was meant for its introduction, not so much as to how the 2900 performs today. When introduced, the 2900 was expected to be a killer card, and history shows how bad that went off. If the driver developement had been as good a year ago as it is now, the intro would have been much better, with a lot more 2900s selling. That said, as you state, it was and still is is overpriced.

Even when spreading rumors, I tend to be conservative      

Hmm, Phin, I like the sound of that info (seeing as I'm running a 2900XT).  I can't confirm any of that, but I do know that it runs everything I throw at it quite well (and significantly better than when it was new).

are there any benches around of 2900xt with new drivers?
did a little google and found a thread about crysis performance but nothing else

I am not too sure if the 4xxx series "r700" will be too good. It seems like a patched together upgrade of the rv670 with more ROP's issued to compete better with the now ancient nvidia 9 series. Some of the older specifications of "r700" were calling for native dual core, and over 1ghz clock speed at 45 nm / 40nm half node. Im not too sure that the 4xxx series is really a new generation, so much as a redesign.