I'm interested in learning Scheme, and keeping my fingers crossed that they can come together and specify some kind of "batteries-included" standard library. Otherwise, I'm afraid I'll only be able to fiddle with Scheme for an hour or two on weekends and get my real work done with one of the "popular" languages (i.e., Perl, Python, etc.). Yes, I realize PLT has some batteries included but I'd prefer a community stand…
PLT has the most batteries of any distro I've ever seen (disclaimer: one of its authors was my undergrad advisor). That is, PLT is (a) free, (b) mature, and (c) has a fair number of modules written by people other than the developers of the language.
There's no sense in waiting, just dive in. If you don't want to use PLT, Bigloo can call Java libraries---solving your battery problem in a different way.