According to a slashdot article, the cheapest version of Windows 7 willbe limited to opening 3 different applications at once, ie you could run itunes, firefox and ms word, but then would be unable to open anything else. Although apparently multiple windows from the one application only count towards 1
If true, and if it ends in the final release, this takes Windows 7 from 'one of MS's better programs' to 'an even bigger cock-up than Vista' in my eyes
http://tech.slashdot.org/article.pl?sid=09/02/09/1348255&from=rss
Edit to avoid me having to say this to everybody who joins
XP starter and Vista starter had the same limitation, but were only sold in 'emerging markets'. 7 starter, however, is available worldwide, but 7 home basic is not, meaning that if you do not want starter, you will have to fork out for home premium
Edit2 - MS has changed their stance, now removing the block that would have limited Windows 7 starter users to 3 applications only
http://www.aviransplace.com/2009/05/30/microsoft-kills-3-app-limit-for-windows-7-starter-edition/