"Is the bootloader getting bigger or smaller?"
It hadn't occured to me that it could get bigger [checking datasheet...], looks like the bootloader can take up to 4096 bytes on the 328, yeesh.
I haven't heard anything in a while about making a smaller one. I haven't worked on converting the pboot uploader loader to java due to other priorities, and since the "gate" for 0013 was missed.
Here's the one I've been playing with, but it is a fairly large deviation from the development norms, but it is 512 bytes:
http://www.avrfreaks.net/index.php?module=Freaks%20Files&func=viewFile&id=3085&showinfo=1