Wow that was quick. I've had my bike for about a month or so and I'm already thinking of upgrading some parts. I was going to ride it as is but I guess I've been bit hard by the road biking bug.

On my MTB the best upgrades I made were on the cranks and the wheelset so I'm assuming that would be a good place to start on my road bike too. I'm looking at a Mavic Ksryllium Elite wheelset, which my LBS can get for me at a good price, and an FSA Gossamer crankset.
I had Mavic wheels/hubs on my MTB so I'm not too worried about using them on my road bike but I am a clyde (6'5" @ ~230) so I'm kinda concerned about the durability of them.
The new cranks and bottom brackets are totally foreign to me. I'm hoping I can get just cranks to replace the Tiagra ones I have now but I see that the FSA cranks come with a new/different BB. What happened to pull off the old cranks and put new ones on? Any input on the cranks would be appreciated since I'm still learning about the new style stuff.
Ok so any advice from the group? Thanks as always, you guys are quite helpful.