Permanent use of branch, making main trunk obsolete (good or bad idea ?)

[Chris]

We have branched a module for a future version with new features.
Currently maintenance fixes are carried out in the main trunk.

Maybe we should have done maintenance fixes in the branch, and used
the main trunk for the new release.
However, we have done this backwards, i.e. new release in branch,
maintenance fixes in main trunk. We have merged the maintenance fixes
into the branch from the main trunk.

Is it a bad idea to go forward by developing new code in the branch
(and 'pretending' it is the main trunk). We will then in future branch
off from this branch and so on.

My worry is that because of CVS internals, this might be a bad idea.
The alternative is to make the effort to merge the branch back into
the main trunk, and create a new branch at that point for maintenance
fixes.

Can someone please advise on this ?

Thanks in advance,
Chris.