One great thing Ive noticed coming from a lot of the discussions recently have been some of the game component breakdowns, which I think are absolutely necessary in understanding what you are providing the player. For instance:

experience point system - a non-item based powerup

I think these are the kind of truisms that need to be propagated around so that everyone knows exactly what they are doing when they include an experienced based system.

Id love to collect up everyones takes on things and wrap them up into a compilation article.

-Geoff