Too much memory used?

Nah, that's pretty normal I believe. I use the same amount of ram with itunes opened and quicktime and dreamweaver. But quicktime isn't doing anything, only being standby, and dreamweaver isn't worked on.

You might say "well I still think something's not right". Well mail is pretty intensive, even if you don't use, but it is opened. If you watched last keynote they said that mail uses (way) to much resources while not really active/used.

So it's pretty normal, don't worry.