Only way an enthusiast comapny to approach nVidia at this point in the game is really to approach them from all fronts. Price is a big factor, espceailly with ULI coming out with their chipset (and many of their boards are very cheap too) - and if you've noticed there has been a lot of price cuts going on lately (Neo4 SLI and ABIT AN8 SLI can be had for sub $100, etc). Basically ULI and VIA have got the budget division covered, ATI's got the integrated graphics solution covered, nVidia's got the rest covered. With ATI coming into the market this late in the game ... we'll have to see what goes on.
ATI's definately been in trouble lately with their manufacturing process. Delay of next-gen cards, now coming out with a crossfire board nearly 6-8 months after nVidia came out with SLI), and more. Although I'm not sure why this should be a problem, ATI's revenues went up by 30% last year (don't quote me for an exact figure) due to their RS480 chipset appealing to the OEM market.
Edit:
Their new chipset doesn't promise much advantage to the triad & true nForce4 chipset, except for the High Definition Azilla audio, but this is with the SB450 southbridge (no support for SATA II, no NCQ, slow USB implementation + more cpu overhead). Once the SB600 gets released there should be a more compelling reason to upgrade to the ATI chipset, but they've got to work on the price.
Their Crossfire implementation is comparable to nVidias, the biggest disadvantage being the "Crossfire master" card you have to buy. Not as flexible as nVidia's SLI.
Once ATI does do something, however, they usually do it right. Someone made a comment about ATI "playing it safe" - agreed.
<-- Happy owner of a 9800Pro.
-The Pentium Guy