At higher resolutions, the 4850 loses out, not the 9800GTX+
According to techtree:
1) Crysis at 1280x1024, high detail, 2xAA, 9800gtx+ gives 38fps and HD4850 gives 40fps
2) Crysis at 1600x1200, high detail, 2xAA 9800gtx+ gives 19fps and HD4850 gives 26fps
3) Crysis at 1920x1080, high deatil, 4xAA 9800gtx+ gives 13fps and HD4850 gives 23 fps
you can even play crysis at fullhd
Accroding to pcperspective:
1) Crysis 1280x1024 0xAA 8xAF, 9800gtx+ gives 36fps and HD4850 gives 32fps
2) Crysis 1600x1200 0xAA 8xAF, 9800gtx+ gives26fps and HD4850 gives 25fps
3) Crysis 1920x1080 0xAA 8xAF, 9800gtx+ gives22fps and HD4850 gives 21fps
Remeber, here Antialiasing is not applied and if it is, 9800gtx+ will seriously suffer due to AMD superior SP's
According to LegitReviews:
1) Crysis 1280x1024 high detail, 9800gtx+ gives 35.5fps and HD4850 gives 34.8fps
2) Crysis 1600x1200 med detail, 9800gtx+ gives 44.4 and HD4850 gives 41.1
3) Crysis FullHD very high detail, 9800gtx+ gives 16.8fps and HD4850 gives 15.8fps
As you can see in all those benchmarks, as the resolution and level of detail increases, the difference between the two cards decreases.
Similarly, as the time goes on and when new games are released utilizing power of ATI's new architecture, it will be a whole different story.
Moreover, if you want more HD4850's crossfire is the best among 10k cards.
and when you do a crossfire, you save another 2k when compared to nVidia's SLI config. That means that you save a total of 4k.
eg: Take a look at this link *www.guru3d.com/article/geforce--9800-gtx-sli-review-plus-model/5
Look at the HD4850CF vs 9800gtx+SLI comparison.
4850 in CF easily beats 9800gtx+ in SLI mode in the game COD4.
PS: why didn't they give similar testing for crysis game