How long after release will the last LTS get a HWE kernel?

The Vivid release is just around the corner so as a 14.04 user I'm curious to know when there'll be a supported kernel upgrade available. I have several machines running on Utopic's kernel and I'll have to upgrade within 3 months. I'd like to get testing started sooner rather than later.

I've been trying to find out when (and I'll include as far as I've got as an answer) but if anybody knows of a plan, I'd be very interested to know.

We have seen a few HWE stacks now so can can look at the repo-creation dates for a bit of historical background:

• trusty-updates/linux-meta-lts-utopic 2014-11-24, 32 days after Utopic
• precise-updates/linux-meta-lts-trusty 2014-04-25, 8 days after Trusty
• precise-updates/linux-meta-lts-saucy 2013-11-08, 22 days after Saucy
• precise-updates/linux-meta-lts-raring 2013-05-05, 14 days after Raring
• precise-updates/linux-meta-lts-quantal 2012-11-14, 27 days after Quantal

An average would suggest something like 1-2 weeks for a -proposed update and 3-4 weeks for an -updates update after the release date.