I continue to discover stuff about New Blogger. First of all, if you view any single post on this blog by itself (click the permalink to do this), there's a sidebar item called "Previously on Byzantium's Shores". This used to consist of a list of the eight or nine posts immediately preceding whatever particular post you'd be reading, but now it seems that this always lists the most recent eight or nine posts published. In other words, if you go to some post from two years ago in my archives, the "Previously on..." list would be the eight or nine posts prior to that one. Now, the post from two years ago will list the posts that have appeared today. This makes that feature a lot more useful, I think -- the idea is to encourage people arriving at the blog via very old posts to check out what's new.
I also like the way that when you make a single change to your template, BAM! It is applied automatically to every post, and you don't have to republish the entire blog. (Republishing the entire blog was always a big pain in the ass.) I suspect this works by having Google/Blogger generate each individual post-page on the fly, rather than actually creating separate pages for each post, storing them on some server somewhere, and then loading them appropriately. (I wonder what effect this has on search engine spidering of the archives, though.)
The idea of labels needs a bit of work still, it seems. Currently there's no automated way for me to stick a list of my labels in the sidebar somewhere, so you can load every single post labeled a certain way. This is possible for bloggers using one of the free templates Blogger provides, which already contains the necessary code, but they haven't got round yet to making this possible for dinosaurs like myself on older templates. (I can probably hand-code this utility into my template, and I probably will, but it's not going to be a huge priority.)
Also, if you do click on one of my Label tags to get every post in that series, currently with my template you only get the most recent 20 or so posts with that label, and none of the ones farther back than that. This makes labels less useful to me at this point, although I will still be using them in anticipation of the time when these issues are resolved.
I have not yet attempted to post directly to the blog via Google Documents.
And there's my progress report for New Blogger. So far I'm impressed. Looks like I'm staying on Blogger for the foreseeable future!