Novell did a survey last year to find out what ten apps people most wanted ported to Linux. I've put a copy of the results into our wiki here: http://wiki.winehq.org/LinuxApplicatonRequestSurvey
Wine seems far enough along that it's not unreasonable to consider getting all ten of these apps working over the next year. (One of them already works great: Lotus Notes. So that's one down, nine to go...)