First of all, if I were you I'd sort them by "sender" as Dave suggests in the FAST CD. That will probably enable you to dump a bunch right off the bat. Then I'd re-sort by "subject" and that will probably make it clear that another bunch can go directly to trash without passing GO (for example, anything with "Viagra", "Cialis", or "Make Millions Online" on the subject line is a goner).
Now I'm guessing you're down to a hundred or less and you can start working through them systematically using your two-minute rule, reference folders, and other folders as appropriate for you. (I also set up a "Review Weekly" folder and a "Review Monthly" folder in my e-mail. It's amazing how helpful they are - they mimic my hard-copy tickler file and I just have to follow the discipline to look at them on schedule).
You might find it necessary to re-sort on "Sender" and "Subject" & purge a few more times while you're getting the inbox cleaned up, but if you can ever get the inbox to zero I hope you experience what I did when I finally saw it for the first time. Just remember that's not the end, now you have to work through those folders you sent the emails to and make good N/A decisions - otherwise the system isn't working for you.