I have read today that Kubuntu might not be supported after the 12.04 release. Is this true? and if yes, what other ubuntu alternatives have the same fate and why?
On the IRC chat for Kubuntu yesterday, the Kubuntu Devs were a little disappointed they lost paid financial support from Canonical, but they will continue to develop and support Kubuntu regardless of the financial support. Lubuntu, Xubuntu, etc. all are similar in that Canonical does not give them direct funding.
To give an actual answer to what is actually "supported" 12.04 and later, in terms of "Official Derivatives" (derivatives which are official, to some extent, regardless of Canonical paid financial support), the following are, at the very least, the current derivatives which are still actively considered "official":