It'd be lovely to get both next gen machines (or all three if you include the joke Nintendo brought out). Unfortunately we have to pay for them ourselves rather than have them gifted by the government, though, so I'll have to pick one.
I've no idea which it'll be. I'll have to evaluate both when details are known.
I guess Microsoft has a very marginal head start over Sony in claiming my money - gamerscore and achievements are stupid and worth nothing... but I don't want to throw them away! Which makes them (and Sony's trophies, and whatever Ninty use, assuming they've finally caught on) clever additions to the machine, to be honest.
Gawd but I wish we had some solid details on the machines. I'm sick of all the rumours. There's loads that all sound plausible, but if they differ from each other, as they always do in some way, then realistically we know next to nothing.
For instance, rumours abound lately that the xbox processors are running at 1.9GHz, rather than the 1.6GHz previously touted. Either sounds entirely plausible, but until we know the definitive specs all the "leaks" might as well be complete guesswork for all they're worth...