For users with 32-bit Windows 7 or Windows 8, please note the following from Sony Creative:
"64-bit operating systems are the best choice for high-end performance. By focusing exclusively on 64-bit operating systems like Windows Vista 64-bit and Windows 7 64-bit, Vegas Pro 12 overcomes many of the limitations of legacy 32-bit software/hardware architecture, enabling users to enjoy superior performance and improved stability for memory-intensive projects and formats."
In other words, Vegas Pro 12 is only for 64-bit Operating Systems. The advantage of this is that they can direct their resources to just one version. The bad news is that there are still a bunch of people who have to stay at 32-bit. For Sony Creative's sake, I hope the quality of Vegas Pro 12 is much higher than 11 since they only had to work on one system. They are running out of excuses if the quality is poor again.
For me, I'll learn Edius (and hope that one day I'll get some 64-bit drivers for two pieces of equipment that I have to use).