Barriers to Agile Development

I just ran across an interesting blog post RE the Barriers to Agile development at

barrier to agile development

Personally, I can see how Agile and TDD work. MY personal biggest barrier is that MOST of my development time these days is spent porting REAL legacy code - VB 6.0 stuff (some of which were ported to VB6 from VB3!)

I've read
Michael Feather's Working Effectively with Legacy Code and Joshua Kerievsky's Refactoring to Patterns.

The BIG problem is that there are very few tools to get VB6 fat client NON DLL applications under test before you try a port, and if you have seriously UGLY code (and some of this stuff belongs on the daily WTF) you are basically FORCED to do the port, do hundreds of minor repairs to try and get your code running, and THEN instrumenting your code. Distinctly NON optimal.