The old software model is outdated

I'm trying out the beta for Microsoft Office 2010.  This beta program is a great marketing option for Microsoft.  At this point they allow almost anybody to download their software and use it.  But it comes with a price, the software will expire in October 2010.  At that point many of us will be hooked on the new features and will have the need to purchase the software.
The product I've used the most in this new Office suite is Outlook.  It is significantly improved and finally has some much needed features such as message threading.  Outlook also gets the Ribbon functionality, with its graphical menu, which it only partially had under 2007.

This is bad.

It isn't bad that we have those functions.  It is bad that we had to wait until now to get it.  The Ribbon was one of the main features of most of the other Office 2007 products, but apparently the Ribbon hadn't been completed in Outlook in time for the 2007 release.  So we got what was ready and had to wait until 2010 to get this feature integrated into Outlook.  And I get to buy the product again.
Don't get me started about threaded messages.  This is the feature that groups your messages with the same subject line together.  I've been enjoying that feature for at least four years in Gmail and was hoping for it in Office 2007.  Now I can have it in Outlook 2010.  If I want to buy the full product.

What is next?  Office 2012, 2013?  Will I wait three years for improvements?  This is no longer the way to run a software company.  Improvements should be incremental and more frequent.  Cost structures should be changed.  Microsoft will realize this at some point but it will come at the cost of lost revenue.