Should I wait for the release of Windows 8 before I buy a new computer?

Hi, I currently have a computer running the now-obsolete Windows Vista Home Basic operating system. My mother's computer, by comparison, is Windows 7. I live in a home for adults with special needs, and I have a deal with a resident that he is going to buy my current laptop so that I have the money to buy a brand new computer. I was thinking of buying a Windows 7 Home Premium laptop and upgrading to Windows 7 Ultimate (the upgrade being needed to run Windows XP Mode), but it seems that Windows 8, the successor to Windows 7, may be released later this year. I am wondering though, is it likely that any version of the upcoming Windows 8 would run Windows XP Mode? If so, does that mean it may be worth the wait of an extra few months just to get the latest version of Windows? Thanks in advance for your help, guys!