I do agree. I think a e-smith of today can still survive for some time and still be a good server. What the e-smith really is is a more or less standard linux with a very smart configuration system at the top.
Most of the building blocks of the e-smith is system modules it has in common with a lot of other Linux distribution. If a secutiry hole is found in one of theese system blocs lets say as an example the sshd semon, the general Linux sosiety normally will make a revision that norally will be avalable, after some time, more or less for all Linux distibutions, including the e-smith.
When it comes to issues related to security and security updates I think the e-smith is not only a Mitel produckt but also a open source Linux produckt. So even if the Mitel company should stop this project, "the Linux and open source part of it" will still have the oportunity to live further on.