Automatic rollout of VLAN (and other) configs to Procurve switches
Solution 1:
Last time I was working with a lot of distributed non-cisco switches and had to do tasks like this budgeting was an issue so I couldn't use any of the paid solutions for it. I went back to the basics and used expect.
It worked well in my situation, however if you don't have your trunk ports all on the same port of a switch it may get complicated depending on your amount of variance.
These days there is also expectpy for those who prefer python to tcl.
I'll admit the option is a bit arcane for most admins I've worked with. Also you're correct RANCID watches for config updates, it doesn't deploy changes.
Solution 2:
NOC Project does more or less what you describe, plus a bit more. It's a Django application that handles network resource tracking, configuration management and pushes out to devices. Think Puppet for Network Operators.
The caveat is no Procurve device support right now. However it might be an option if you're consigned to writing something anyway.