well done! I published my MSc dissertation and recently found it was cited by someone :-) problem is, its in a 2011 journal and I can't see why/how they've cited it - they could have slated it for all I know, so holding back judgement :$
It will happen alot more as the Ethos website and the various Open Repository websites develop. It's a good thing that all this information that once gathered dust is actually accessible.
The one caution I'd make is over plagerism and copyright protection. I would have at least the key parts of your research published to journal too under your name as at least one of the authors. Journals are still far better for active distribution of published data, whilst theses still just sit there waiting to be found.
WOW!! WOW!! WOW!! I'd swing from the chandeliers and break out the bubbly if that happened to me! It must be a truly amazing feeling. WELL DONE! It means that all that hard work actually MEANT something to someone else. And isn't that what it's all about?(up)