Well done, Windows XP holdouts. Microsoft (NASDAQ:MSFT) is so desperate to get you to upgrade that it's offering a $100 instant rebate to those who upgrade to a new Windows 8 PC. Fool contributor Tim Beyers explains the implications in the following video.

Upgraders purchasing a machine costing $699 or more via Microsoft's online store are eligible for the offer, which also includes 90 days of free support and a free data transfer between machines. And what of those who don't upgrade?  Microsoft will stop offering security patches and support for XP machines on April 8.

Tim likes Mr. Softy's plan, saying that Microsoft needs to get more users onto its newest Windows code base in order to focus resources on improving Windows 8 and related applications. Especially now that economics of the OS business are changing: Apple (NASDAQ:AAPL) ended its policy of charging for system software upgrades in October, when it began distributing its latest OS (i.e., Mavericks) free to existing Mac users.

Can investors expect a rush to Windows 8 as a result of the new incentive plan? Tim says there's no way to know for sure. Yet he also argues that Microsoft had little choice to but take extreme steps. At least one estimate pegs XP's installed base at 15% of all PCs operating worldwide -- a staggering number that, as of April 8, will become a lot more vulnerable. Now it's your turn to weigh in. What do you think of Microsoft's XP upgrade strategy? Leave a comment below to let us know where you stand.