Will probably upgrade my MacBook Friday evening (if I get my retail Leopard before). I'm leaning towards a clean install... just to get rid of LOTS of junk that has been building up the last year or so (since I changed the HD).
The (brand new) office iMac (just received yesterday 🙂), on the other hand - probably won't be upgraded until some time into November, even if I get the (not even ordered yet) upgrade disc on time. I'm in the middle of a couple of LARGE projects, with imminent (or already past) deadlines, and wouldn't even have time for an upgrade, even if I wanted to.