Not sure where all of these 3mb/1mb numbers are coming from but when I do fresh installs of SQL 2005 or 2008 (which I do a couple of times a month in the classroom from a dvd) the new databases always default to 2mb for mdf and 1mb for ldf and that is for dev, standard or ent editions. I also checked my production servers on 2005 and 2008 and I could not find one that defaulted to anything else... great question and sort of has me thinking, but that creates 2 more questions:

1. Who is going to use a 2MB database?

2. Didn't someone say "size doesn't matter"? 😉