Mac Apps Release Dates?

Does anyone have a list or website that displays the release dates for new Mac apps? Specifically new Universal apps and Microsoft Office 2007?

Not really. Mac apps generally don't have specific release dates. The best one can hope to see is a broad prediction like Q4 2007 or something like that.
This practice will differ from developer to developer, so there really is no way to get a "master list" of apps.
If you want to check to see if an application is Universal, you can search the database on Apple's site here:

http://guide.apple.com/universal/

Office 2008 is scheduled for release later this year. There are alternatives, such as NeoOffice (which is also free), or Mariner Software's office package.