Julien Lavergne generated a final iso lubuntu testing release before announcing the public release.
The download is available here: http://people.ubuntu.com/~gilir/lubuntu-lucid-20100430.iso
The release fixed a problem with installed languages, and includes some bug fixes for pcmanfm/libfm.
Please test it and report any blocker you are encountering that would stop this release to become the lubuntu 10.04 release. This iso should be the last one if no other problems are found.