There are enough hacks out there that with a bit of tinkering you can actually turn Blogger into a half-decent platform. Nevertheless, there are two features in particular which I think could still use further improvement:
1) Recent Comments. The recent comments hack only picks up on comments from posts on the current page. It can also be a bit slow if there are a large number of comments to sort through. Both these problems would be avoided if we could create an appropriate RSS feed for comments. I have no idea why Blogger don't provide this themselves (surely it wouldn't be that hard for them to do?), but it seems like something external users could create for themselves. We receive email notification of each new comment, after all, and should be able to construct the needed RSS feed out of this.
[Apparently there's some Ning-based hack to create comment RSS feeds, but it involves more template-meddling and - worse - requires XML validity (which this blog apparently lacks). So it would be nice if someone could figure out how to implement my simpler suggestion.]
2) Categories. I'm generally pretty happy with the del.icio.us based "Freshtags" system that I'm using. The main problem is that it's very difficult (time-consuming) to alter the category tags of an old post. You have to edit both the blog post itself, and your corresponding del.icio.us entry. I would like to categorize my old posts which pre-date my installation of FreshTags, and I also often want to change the classifications of some more recent posts (say if I decide to introduce a new category). But it would just be too much work at present.
This needn't be the case, however. Someone with better programming skills than me could overcome the problem by designing an "editing program" which integrates control of both your blog and del.icio.us tags.
First, it would import a list of all your blog posts (if there's no more direct way to get the data out of Blogger, one could simply get the user to paste in the list that Blogger displays when you "republish all" of your blog. Though I guess it would also need the post ID# in addition to the URLs, someone else will need to figure out how to get those!). Second, you likewise import your relevant del.icio.us posts. The program then pairs them up, where appropriate, and may highlight discrepencies (e.g. if your del.icio.us post has stored different tags from those listed on the corresponding blog post itself).
Here's the crucial bit: the program would be capable of making edits to both Blogger and del.icio.us in one go. Let's say I scroll down my list of blog posts, and select one from last year which lacks any tags. I click "edit tags", and the program asks me to enter the new tags. It then automatically completes two tasks: (i) it logs into Blogger for me, and edits my post to append the provided list of "categories" (just like you see on this post), and (ii) it posts that blog's permalink to my del.icio.us account, with the tags provided. (Or, if that's impossible, it brings up the del.icio.us posting page with the appropriate data fields already filled in.)
You might even make multiple edits at once, say by selecting from the program's list multiple blog posts, which you want to classify together, and then enter the tags that you want them all to share.
Is such a program possible? plausible? soon-to-be actual? It would be incredibly convenient, in any case, so I hope someone sufficiently skillful might look into it...