I am in the process of upgrading this MovableType edition to version 4.0 and while I am pounding my head against the ground in that they once again made a lot of changes that is going to cause me to have to hire a developer to update the templates.
I probably could do it but I do not need the aggravation. But lets talk about podcast and new media support in MT4. First of all lack of documentation. For a paid product SixApart documentation is still terrible and you have to go through 20 pages of stuff to find a single thing. I would just prefer a PDF with all of the documentation. It would make life easier.
Second unlike WordPress they do not support podcast publishing in a way that is native. You have to guess how they support it and I really quite honestly hate it.
First you have to upload a file which the high majority of us do not do. Most of us push our media to a third party site and then drop in a link. The way MT 3.35 worked was beyond simple because a plugin took care of detecting any enclosures that was embedded in the text. In MT4 the enclosure plugin seems to not work anymore. But if you want to get MT4 to detect a media file you have to upload it and go through about a dozen steps to figure it out.
My Advice to SixApart, look at what the wordpress folks are doing, copy how they did it and implement that in MT4 and make it simple. I can honestly say this version runs slower than MT 3.35 and while the menus are pretty they are less functional then the old design and it takes forever for pages to load.
I am not sure who SixApart built this platform for but for me at least I am not so sure I want to upgrade now.