If you were worried of upgrading to Vista because of compatibility with your programs there will be no difference with Windows 7 unless your processor is capable of running 'XP Mode' and you purchase either Windows 7 Professional, or Windows 7 Ultimate.
The programs that will not run in Vista/Windows 7, you have some options:
1) Abandon the program or find another alternative/update
2) Use XP Mode to run the programs in XP virtual machine
3) Stick with XP until extended support drops in 2014
Microsoft made a tool
Windows 7 Upgrade Advisor to help you indentify the incompatible programs and check to see if your computer meets the hardware requirements of Windows 7.
Even if you purchase the upgrade version, you can not do in place upgrade from Windows XP to Windows 7, you must do a clean install.