Branches and shared dev servers?

Question

So I am using Subversion as SCM for a classic ASP webapp that I maintain. We use feature branching to handle changes that have dependencies or longer term development.

We use shared web servers for Dev/QA, and this is where my question comes in. The central Dev server is a working copy of trunk, and then when I need to see changes on Dev from a feature branch I merge them to the Dev working copy. So far so good, but am I setting myself up for ungoodness down the road?

For example, today an analyst told me I could "remove" the changes I had made to a feature and then merged to the Dev site for a demo--not because the feature was being killed, just because he didn't need to see it anymore. And I realized I could not easily do that. The changes I merged now just show up as local modifications on the Dev working copy and I can't easily peel them out (I'd have to manually revert changes to the affected files, since a full revert could/would kill changes related to other features).

The more I write about it the more I feel like I've answered my own question. Do I need to change my branching strategy--branch per environment? Or do I need to have a separate "shared Dev" site for each branch (dev.mysite.com:4801, dev.mysite.com:4802)? Or is this pretty much how you handle this?