Hi all, I'm responsible for the Blogger importer. It's hard to say why your imports are taking so long. Donncha's blog was pretty huge and he's been able to import it in just a few minutes. The thing to do in your situation is to try again.
Now, I'll caution you before you try again. You must restore your template or choose a new one first. Did you backup your template before you started? If you did, please restore your original template before you retry the import. Your blog might look the same in your browser but believe me, it's different. There's a bunch of junk at the end from the last attempt that will confuse the importer.
I'm going to be very clear about this: don't run the importer again without restoring your template first. You will double the time it takes to get through the import. You don't want that!
If you didn't make a backup of your template, you should go into your Blogger account and edit your template to remove the line near the bottom of the template that starts with
<!--<MainPage> and ends with
Failure to do this step between import attempts will void all warranties (doesn't actually apply because there are none to begin with), waste your time (you should value it more than I do), and possibly cause a meteorite to drop out of orbit and land on your head (I hear this is unpleasant).
Let us know how it goes! :-)
If it continues to be a problem after this remedy fails more than once, send feedback and I'll do what I can to resolve the issue.