Example: in this computer-savvy community, how many use Quickbooks? How many know what it's written in, or used that as a purchase decision? How many decided to commission a rewrite in NET with SQL Server because they're concerned about the obsolete code islands inside Quickbooks or the way data is stored or that fact that its code isn't managed?

You've used this Quickbooks analogy before - IMO, it's baseless. Quickbooks is a horizontal market application. Most developers here work with vertical or spread-vertical market apps or internal apps. It's not relevant to the discussion.

But it's ironic that you brought up Quickbooks - have you been following the issues with Quickbooks running on Vista? Maybe some of the hypothetical questions you're posing might "still" have some significance. <s>