How secure do we think broadband wireless is? Should I be willing to do online banking over a mobile connection? I assume that it's more secure than, say, WEP, but I'd love to be pointed towards any information about how easy cellular connections are to crack.
I'd say it doesn't matter how easy cell. connections are to crack because you are always using SSL/TLS encryption over that, and that hasn't been cracked yet. Somebody might be able to do a man in the middle attack with SSL but then you would get an invalid certificate warning, so you wouldn't continue with the session anyway.
I wouldn't do online banking over a mobile phone connection because there's other possible attacks that aren't specific to the 3G/carrier connection itself.
For example, Bluetooth on many mobile phones can be used for connection sharing with computers, and is not exactly known to be a secure protocol itself.
(Note on that paper, a lot of sensationalist coverage focuses on iPhone, but the vulnerabilities are possible on Android and Windows Mobile)