Joel on Software talks about search in Outlook, and how MS went out of their way to kill a useful third part app:

The only possible explanation is that someone on the Outlook team is getting paid a bonus for convincing people to switch to Gmail.

The story has a happy ending. Last week Microsoft released a patch for Outlook 2007 which fixed the problem for me (I have a lot of big PST files, which, I'm told, is why search was so slow for me). Now I can search old email quickly enough that I don't forget what I was searching for by the time the results come up. It's not quite as fast as Lookout used to be, but it's a big improvement and makes Outlook less of a downgrade.

I'd call that pretty faint praise. Here's a question: why did MS care about Lookout? What possibly reason did they have for being so concerned? If a third party improves your product (thus improving its overall marketability), what's the downside?