Jeffrey says Sharepoint is not a good development platform

http://codebetter.com/blogs/jeffrey.palermo/archive/2007/09/13/sharepoint-is-not-a-good-development-platform.aspx

Andrew and Sahil say

http://www.andrewconnell.com/blog/archive/2007/09/24/6116.aspx
http://blah.winsmarts.com/2007-9-SharePoint_is_a_terrific_development_platform.aspx

My opinion

Sharepoint is not an easy development platform  for newcomers and for one-off projects, it takes a few to get into the "Sharepoint Way", but allows integration with all sort of development tools (source control, testing, even Monad).

Sharepoint IS the best application platform around - especially for content(document) enabled applications (Gartner calls them CEVAs - content enabled vertical applications), with lots of pre-built funcionality and a huge number of APIs to be reused.

Unrelated posts

Sharepoint TDD (Test Driven Development)
http://www.harbar.net/archive/2007/03/28/quotTest-Drivenquot-SharePoint-Development.aspx