Fedora is released every 6 months, as is Ubuntu, so it won't really make things better for you if you move to that.
Ubuntu doesn't have a "most recent" repo - there were plans for a "rolling" repository called Grumpy Groundhog, but it never happened.
You can take your packages from the current branch (e.g. maverick, at time of writing) and backport them to whatever version you are using. You can also look for more recent packages in backports. It's generally best to stay with packaged software unless you know what you're doing.
If you want to always be up-to-date, you could switch to Debian unstable, which is similar, but obviously not identical to, Ubuntu. It has packages released for new things as the maintainers feel like, and because of this, it isn't always guaranteed to be compatible with itself!