+100. I gave up on trying to mold the current Streams into something a bit more reasonable and still be backwards compatible quite some time ago.
That other thread about Converters? Totally related. For example, you can't do what Sven did in the Zn converters without breaking backwards compatability. Nor could you do it reasonably fast in the general case, since fast string -> bytearray streaming works for some streams, but not for others. (which, I guess, is one reason why the legacy converters do string -> string.)
IMHO, Xtreams would be a perfect fit to go with the new FileSystem as well. (using compositing on top of a "dumb" terminal)
Quite sure that it is highly ranked in Colin's plans.
Indeed, with the new FS being almost ready in 2.0 the next big mess to tackle are the streams. Personally I really liked the clean separation of the low level stream features (bytes) and the high-level interfaces to it (converters, characters...) but the question remains on how to integrate them into a running system ;) after having done the FS take-over I see that it's rather easy to create an image that works with the replaced classes. But creating a nice loadable slice / changeset is a rather fragile and tedious task :P