Windows 7 pre-orders start today. While the software itself will not ship until October, you can get a great deal if you order it now.
I wrote down my first impressions of Windows 7 earlier this year. Unlike Vista, I think Windows 7 is a necessary upgrade for every Windows user, especially those still using XP. 7 is fast, and adds a lot of great productivity features, like the awesome new taskbar.
Law firms and law offices should order Windows 7 Professional at least. Windows 7 Ultimate—on which you cannot get a deal right now, unfortunately—adds BitLocker encryption, a valuable option for anyone storing business files on a laptop. (You could always just use TrueCrypt, but BitLocker is a more elegant option.)
Warning: TrueCrypt is not secure. See this post for details and information on migrating to Bitlocker or FileVault.
You can pre-order your upgrade to Windows 7 at Amazon now.