I have 40, 1 in the mail (Heros) and 1 on preorder (Top Gun).
Assuming the expected titles are annouced I expect to buy significantly more by the end of the year.
Harry Potter 1,2,3,4,5
and no doubt lots more when they are announced.
Just as I was starting to get a bit antsy about the format the paramount annoucement renewed my faith and desire to buy titles.
I have £1000 saved up now to spend on something I'm not sure where that is going yet though, Possibly going neutral or more likely I think I'll save up another year and replace my 42 inch 720p plasma TV with a 50 inch, 1080p comercial panel that handles 24fps properly.
Quite a few of the regular posters here have very big high def librarys with a couple of hundred titles.
Edit - Err sorry just noticed this is in the 360 section, I followed the link from the frontpage and didn't realise that maybe you are aiming this at 360 add on owners? I do have a 360 but brought a Toshiba E1 for HD-DVD.