I'm looking for a better calendar widget as well. The built in one SUX compared to the calendar widgets on my old winmo phone. I'd love to get one that makes better use of space (waaaay to much white space in default widget) and shows the next couple appointments.
I used to have the SPB mobile shell calendar widget and it rocked. Something that looks similar to this would be great.
Astrid is a great to-do list with a widget, which also ties into your google calendar and is very customizable. Also free. Might fit your needs, maybe not, worth a shot though.