More than a few of these have been implemented in various mods, check the Compendium and download a few.
Actually, glennrieck, I strongly believe certain features from modifications should be implemented in the game. Besides, there are no known (or accepted) forms for shareware games (one of which Spelunky XBLA will be) to implement modifications in a legal manner.
And clearly, in the case of Spelunky XBLA, there is the large barrier of being on a console platform
. So please, we, the audience
should feed Derek Yu with some of our fine ideas (assuming he bothers to read them)!