Most of the work I do as a Consultant is for Movable Type. But I also work with TypePad, and I've actually seen some increasing activity in this area, most notably from larger companies who may not be ready to run their own MT installation and just want to get something ready and roll it out quickly. For this, TypePad is the perfect platform. It may not be as flexible as Movable Type, but it does offer you plenty of power in a nice interface.
What it doesn't do is give you a few tools that would make things run much better. Though comment pagination was announced a while back, and archive pagination came along afterwards, you still can't paginate your main index (though the code has been added). In fact, you'll find that some customers - even those who pay for the most expensive accounts - can't even use the pagination features that have already been announced! But pagination isn't the only feature missing from TypePad.
What I've found would really be useful are the features that would make managing a network of blogs easier.
For instance, you may have noticed that blogs that share a common set of templates can update that same template set and affect one another. This can be both good and bad. The problem is that often times, you want this feature - to be able to share features across templates - but you need some small variations between blogs that just can't be handled with the standard template tags that give you blog name or description, and in that case, you have to step outside the box. If you're sharing a template set, it won't work. So you have to create another set of templates, which breaks that mold. A minor complaint in this area is that users who don't have permission to modify template sets can still modify the template and effect change across your blogs. Whoops.
One of the more important changes that I'd really like to see - and in fact, I'd like to see this in Movable Type as well - is to be able to rebuild multiple blogs at once. While one of the more annoying messages in TypePad is the "I'm sorry, we had a problem building your template" message that tells you nothing about the problem and then you have to go hunt down which template has the error in it, this would be a great feature. To be sure, rebuilding a number of blogs, any one of which could contain the error, could make it even worse. But assuming you kept on top of this problem - or, even better, maybe Six Apart would improve messaging - then imagine being able to rebuild multiple blogs at once, rather than having to go into them and rebuild them one at a time? That would be nice.
Recently I've had a number of users changing category names, which surfaces a problem in TypePad - the category link is based on the category basename, which is set when the category is first created (and it never changes). This is great because your category links won't break. But when some moron changes the name and you're pointing Petunias to Dilbert, it doesn't make much sense. The alternative is to go find all the entries that belong to the one category and switch them manually, but since TypePad doesn't have a way to list entries by category, you have to browse one screen at a time and hope you find them. Blech. A nicer category interface is a must - allowing you to at least see the category basename, even if you can't change it - and to be able to browse entries by category.
Finally, in a related vein, TypePad really needs to get a decent search mechanism, because sometimes you just need to be able to find something, and frankly, you can't. I have to say that TypePad is actually a rather nice platform that really offers some great features (I'll go into those another time!). For a lot of people, the limitations of "not Movable Type" really won't apply. But there are a few things that really need to be there. What about it, Six Apart?