Okay, so, I'm also a designer and I'd like to throw in my 2 cents on the design without being too pretentious or needy. I also don't want to waste your time, so I'll try to be concise:
I think the logo should link to the user's Dashboard, rather than Basecamp's site. Also, the logo image should be part of this link. I also believe the background bezel/highlight should come halfway down the height of the widget, as with the clock widget.
The subheads (Pending/Completed) take up too much space in the to-do pane. They're actually not even necessary, as you could just visually separate the two between the ones that are checked and the ones that aren't. Maybe even use this guy: http://basecamphq.com/images/greencheck-bullet.gif . Or, if anything, remove the 'Pending' head and keep 'Completed' with smaller type. This may already be a part of v2, I couldn't tell from the screenshot-
Now to the really nit picky junk. The emboss effect on the logo looks a little crummy. Perhaps no embossing would be better, or maybe it can be smoothed out. I also think the drop shadow under the menu is a bit overdone, and should maybe be half as tall.
Lastly, and I don't know if this is possible, but if the API can pick up on the account's custom color scheme, and somehow incorporate it -- well, I can't even describe how badass that would be.
Now I feel bad for being a designer jerk. If it makes it any better I think the loading is brilliant, and feels smoother than almost any other dashboard widget. The type is also lovely, if just a bit too large.
Holy crap I didn't mean to go on that long... Hopefully you're not offended by this or anything, just looking to help. Thanks,
Dave