Having played with Mauku on an N900 and the SDK, some comments:

• One upgrade resulted in Twitter saying "provider closed connection". The preferences box had lost the custom fields (e.g. "username") and I couldn't delete them. Had to delete [font=monospace]~/.microfeed[/url] (or whatever it was) in X Terminal.
• Switching to and from the Overview (the main screen for my use cases) to send a new message is cumbersome. AppMenu entry as well, please.
• I want to be able to subscribe to a search (e.g. #NW09) and have that appear in the overview (perhaps the use of colour to show items which have come from your searches).
• I want a "Share with Twitpic" service so I can take a picture with the camera, post it to Twitpic and have it linked into my Twitter feed in one go.
• Open link doesn't work at all. It shows a list of the URLs in a tweet, but there's no "open" button and double-tapping on an item doesn't do anything at all. All I can do is close the dialogue and type the URL manually.