I think you can reasonably hope to see Live Writer support in the near future. Tom Opgenorth had implemented the metaweblogapi well enough that he was using it on his blog quite a while ago. He had indicated he was still testing it and never said it was finished or ready to include.
That of course was before the blog had friendly urls and also before the blog was moved out of the core projects into the mojoPortal.Features.* projects so its for sure that some code review and changes will be needed. I have had it on my mind and have actually recently harvested the code from Tom's svn sandbox and brought it into the main svn tree though I have not yet compiled it nor even added the code to the Visual Studio project, I moved it there with the inention of integrating it soon though. Since it was basically working I'm hoping it wil be relatively low hanging fruit to get it up to date.
Best,
Joe