I'm in the anti Logitech software boat now too, after seeing their software cause strange issues like breaking Growl. Though I still run it at work, because I haven't found any Mac mouse driver software that supports the MX Revolution scroll wheel yet.

For the photo stuff, I know a lot of people have voiced opinions against iPhoto, but honestly give it a shot. It's going to be on the Mac anyhow, and for me it has never given me problems. I think it all depends on your photo workload. I personally am a point and shoot guy, and I don't take a ton of pictures. My library after 7 years is possibly smaller then what some people take in a few months. I've looked at Aperture at the Apple Store, and just don't see a use for it for everyone. Not knowing your specific photo demands, I'd say iPhoto should do just fine, especially if you are happy with Picasa. That is assuming you aren't bringing over some massive DSLR shot library with hundreds of photos a month over to the Mac.

With the office stuff, the $79 for iWork was worth it to me, but probably the limit of what I would pay for such apps. I have Office 2004 from an old home use license, but I can't ever see paying retail for what Microsoft is asking for 2008. The road to Office 2008 is a really good article series going into each piece of Office 2008 and comparing it to iWork. Probably work a look to see exactly where your needs are, as iWork is still very basic in some areas. For me, iWork fit perfectly with my occasional and personal use of office apps. But if you have a strong need to exchange MS formatted docs with people a lot, it may be worth it to spring for the full Office 2008 suite.