ability to filter out user agents. 34.1% of our errors are from googlebot.
Unsupported browsers is here, please vote: http://errorception.uservoice.com/forums/132896-suggestions-and-feedback/suggestions/2355329-automatically-mute-a-certain-browser
Filtering UA would be nice. Right now I just determine the UA via PHP and don't include the script in case of bots.
We would also like to filter out errors from unsupported browsers. We don't support IE < 8, so I'd like errors in IE7 and lower to not count towards my monthly allotment. It also really adds to the noise.