The only problem I see with it is that, it's new, yet it's already 2 generations outdated.
This is just my $.02:
1. Skip the Vista OEM license and save $180, download the Win7 64 RC. It's completely free, and does not expire until June 2010. I have both Vista 64 Ultimate and Win7 64 RC. I use the Win7 build more often than the Vista. I have not had any problems at all with Win7.