Windows 7 has been under test for a few months. Due out October I think (but not sure whether it is start or end). I know a number of PC users who have stuck with XP rather than use Vista, because V had problems, but where V got bad reviews concerning software compatibility, there has been nothing like as much flak about Win 7.
Many businesses didn't touch Vista, and Dell and others carried on selling machines with XP on for 18 months after Vista launched.
I'd personally look in the 250-350 price mark. The thing is that laptops (unless being used by someone for mega complex processing) don't need to be that powerful (otherwise they're power hungry too, get hot, and run the battery down quickly).
Part of the cost for any PC is the CPU, and the most powerful 3+ GHz can add 100 pounds against 'run of the mill' 2 GHz CPU
For word processing, browsing, playing music, and managing photo collection, it's arguable that a 250 quid PC will do as well as 500 quid PC.
However, laptops are more costly than desktop/mini-tower/tower PCs because they have to work harder on the design, use low power consumption components, and squeeze out better performance with as little weight as possible.
Also, you're getting a 75+ quid screen as part of the deal... Hence the 300+ pricing for so many machines.
XP support was extended, but I see Vista being a different category. If Win 7 takes off with business, as expected, then there may well be a flood of new apps which work best with 7 and the long-standing "works with Win 2000, NT, XP" might go out the window.
In the past there was Windows 2 and 3, running in 8 bit mode, then Win 95 and 98, 98SE, which had 16 bit mode. Win XP has lots of 32 bit software and now things have moved onto a new level with 64 bit processors.
Assuming you want to buy sooner rather than later, then there's that Toshiba at Comet for 360 pounds which has 4 GB of RAM, 250 GB hard drive, and there's a Win 7 upgrade option. It's certainly one of the few 4 GB machines around for the money, and Toshiba laptops have been respected since the 80s (orange screens back then).
In my view, better to have big HD and plenty of RAM from day 1, as adding anything later is a pain in a laptop, and those two are perhaps 100 pounds of value compared with a machine having 160 GB HD and 2 GB RAM.
If you can hold off purchase, you'd perhaps get it with Win 7 installed from day 1, and that way you'd have no qualms about support calls if anything wasn't working 100% - no chance to point the finger and claim you did something wrong when installing Win 7.
Sorry if that sounds ultra spoilsport, you want it, and you want it now, but I'd hate for anyone to buy and then feel rally fed up that their friend / neighbour / work colleague laughs at them and say, I waited a week and it was all installed and faster than Vista...