This Question is Answered
Check out some of Dell's laptops, they have a line specifically for Vista compatibilty.
As far as 64bit goes, yes - for desktop and portables, the gaming industry is the driving force. For servers, however, then I would think Microsoft would be a major factor (as in fact they are for gaming, as if you're talking PC gaming, you mean Microsoft), with their given statement of intent to move to 64bit only servers in the next iteration (after Server 2008). Already the preferred download for evaluating Server 2008 RC is 64bit; Exchange 2008 is 64bit.
Modern games are starting to tax 2Gb RAM systems, and with most people buying the dual channel ram upgrades, the next steps are 3Gb or 4Gb. With the price of RAM so low these days, a lot of people may consider it an good investment to buy another 2gb, and find out their desktop only shows 3 - 3.5Gb of the total because of the memory mapping limitations of 32bit Windows. About 18 months ago, 2Gb was considered a huge amount of RAM for a gaming desktop. Course, that was before Vista hit...
Additionally, in the enterprise (the largest OEM market), security is going to affect OS deployment decisions. With microsoft's 64bit kernel inherently more secure than the 32bit one, it become more attractive as a base platform to standardize around. Hence why Dell, HP, etc. offer their desktops in 32bit and 64bit preconfigured formats.
Performance increases are documented for true 64bit game executables. Running 32bit games in emulation under 64bit OS is not likely to show an increase in performance, though the all round computing experience may be enhanced through native services and applications performing better. I am unable to find it now, but Microsoft published a case study of how moving to 64-bit Server 2003 on their WSUS clusters decreased load and increased throughput, serving data faster thant their previous 32bit configuration.
Of course, all the above is my opinion and not necesarily fact, so please enjoy a little salt with it
