Tomorrow (Tuesday, January 30th) is the big day. That's when Microsoft's Windows Vista operating system, long in the making and refinement, and it's Office 2007 suite will be available for purchase by the commonfolk.

Only this time around, you can choose between buying online and downloading or going to the store and picking up a cardboard box and CD. This is the first time the OS and productivity suite have been made available for purchase and download online.

On Tuesday, the Windows Marketplace site will allow you to make your purchase and get that immediate gratification, all from the comfort of you own easy chair (or whatever seat fits the bill). The Marketplace system uses their Digital Locker, which allows you to purchase software online and get back at it later - you can store your purchase online.

Vista delivers some significant and (I think) important security enhancements, so from that standpoint I see it as something akin to a must-have. However, with all the versions being shipped and the relatively complex hardware requirements to review before you purchase, be sure to take the time to see what you really need.

Office 2007 is something I can recommend whole-heartedly. I have been running it for a year or more in betas, and the release version, which I have been using since the day it was made available to volume license customers, is excellent.

What editions can you buy online on Tuesday? Microsoft will let you purchase and download upgrade copies of Windows Vista and and full copies of these Office editions:

• Windows Vista Business
• Windows Vista Home Basic
• Windows Vista Home Premium
• Windows Vista Ultimate
• Microsoft Office Home and Student 2007
• Microsoft Office Professional 2007
• Microsoft Office Standard 2007

(via Trevin)