Getting the new body also means saying goodbye to two lenses that I knew wouldn't function on the Mark II. One is the (rather average) 18-55mm that came as part of the 450D kit. The other is my Sigma 10-20mm. I've only used the Sigma a handful of times and was put off by the distorted edges. I could've worked around/with it but it's too late now.
I only have two lenses that fit the new body: a Canon 100mm macro, and a Canon 24-70mm f2.8 L. The macro is my favourite and has been ever since I bought it. I use it for close-ups (sometimes teamed with extension rings) and portraits. It takes stunning portrait shots. I'm hoping now it's on the Mark II, it'll take uber-stunning portraits.
I also found out that I needed to buy new, CF memory cards. The numerous, expensive SD cards I'd bought for the 450D don't fit the Mark II. The Mark II doesn't have an onboard flash, either, but luckily an old flash I used with my (film) Praktica fits it.
I'm all set to go. Now I just need to find something or someone to shoot. Watch this space!