2003 vs 2007/2010 - yeah, I think it's just that you're used to it.
There are a few issues in converting older databases to thew newer versions, b/c some of the older code sometimes breaks. Microsoft has a whole list of changes that point out what might break. I had to change one small process, myself, due to the 2003 -> 2007 change.
From what I'm hearing, 2010 has a few more features, but in some ways, doesn't seem as nice as 2007 - at least from a visual perspective... don't know if it's any better/worse functionally, b/c didn't take enough time playing with the beta demo of it while I had it installed.
It would do you good to go through some intro type tutorials so you can learn where all the different menu items and such have moved to as well. It can be a pain at first, but once you get used to it (I think, and most people I've talked to agree), the ribbon is really a nice way of doing things.