headers from metadata

Hi,
 I was looking over the things that could be speed-improved in the new
yum-HEAD code and the biggest speed hit I get is that for the depcheck
transactions yum (and up2date, afaik) the headers  are still needed. You
have to pack the rpm transaction set with _something_. I'd love to be
able to make an rpm header out of the xml-metadata I already have.

I remember a while back this was being discussed. I was curious what the
status is of that code? if I could write a method to the packageObject
code like po.makeHeader(), I'd be a real happy camper.

I guess it's either that or look at Adrian's vTransaction in more
detail.

Thoughts?
-sv