The alpha version of the upcoming Smb4K 1.1 has been made available. It comes with many improvements and fixes as well as a (yet unfinished) plasmoid. If you want to run the plasmoid, you will need KDE SC 4.10., otherwise KDE SC 4.8 or even earlier will do.
Although not thoroughly tested yet, Smb4K should already be quite bug-free. However, the plasmoid is still under heavy development and is not ready for daily use.
I would like to encourage everyone to test Smb4K and report any bugs you find to the bug tracker. Please note the version you are using in the ticket.
For the list of the changes since version 1.0.x, see also the ChangeLog file within the tarball.