Yes, absolutely!
I have been away on other projects for quite some time now but there is no question that Kolab2/Gentoo will get attention again.
Let me give you some idea why there is currently no visible movement for Kolab2/Gentoo:
While Kolab2/Gentoo-2.1 worked it has also shown a number of really severe drawbacks.
The upstream Kolab developers choose OpenPKG as the base distribution for Kolab. This was about having a very well defined (and thus restricted) environment that makes it easy to code on the server. Gentoo on the other hand is all about choice. And both systems don't match very well together.
A resulting problem of the OpenPKG choice has been the coding style within the Kolab project. The choice of the restricted OpenPKG system allowed the developers to not care about some common coding practices that would have allowed to easily transfer the Kolab specific packages to other distributions.
This is a thing that I fixed partially in Kolab CVS upstream (2 out of 4 packages). The full set of fixes will probably only be ready with 2.3.
Another problem is the way the Kolab configuration is being created. This does not work the way I did it in Kolab2/Gentoo-2.1. On Kolab2/OpenPKG you are not free to choose the versions of the component that form the Kolab server. On Kolab2/Gentoo you can but that disrupts the configuration system. I'm writing a new configuration tool here that allows to write configuration depending on the installed versions. This will also still take a while.
I am aware that the current 2.1 version would already need some care and fixes but currently I'd rather like to spend time on the required upstream things before the overlay moves again. As mentioned before it will probably take another year or more in order to get this into reasonable shape for Gentoo. But there is no question that I'll invest the time even if there are times where I may be quiet

Cheers,
Gunnar