Microsoft Planning Web-Based Business Software

In response to Google Apps for Your Domain, Microsoft is also planning to release free web-based business software. The software will be ad-supported, but a paid, ad-free version will also be available. From the article: 'Revenue from software licenses for Office and the Windows operating system accounts for a bulk of Microsoft revenues. The challenge for Microsoft will be to make sure a free or, possibly, a subscription-supported version of Works won't hurt sales of its dominant Office software, which accounted for a quarter of the company's $44 billion in sales last year.' Would you choose an ad-supported online version of Microsoft Office over other free options like OpenOffice or Google Apps for Your Domain?