I (anonymously) posted a reply on Groklaw with similar content as I'm stating here.
The mount command is a standalone piece of software. It's unlikely that Twin Peaks' patent is practiced in the mount command, but in some kernel module. Hence, providing the mount command and their patented software is mere aggregation, and wouldn't provide a GPL license to the rest of the software even without some of the other arguments posted by others. Twin Peaks could also likely write their own mount command which does not infringe on Red Hat's copyright, which would eliminate the infringement, and make an injunction moot. Then, one gets into what the maximum statutory damages would be for distributing mount. It's unlikely to be per per item, but for the work being infringed. Twin Peaks would have to spend some effort to rewrite the mount command, but that would cost less than the amount of damages they expect to collect. Alternatively, Twin Peaks' sales might be poor enough that they could stop selling their product without a significant change in revenue, as SCO did. Finally, if Twin Peaks downloads another copy of util-linux and releases their mount sources with future distribution of their product, US courts have never weighed in on if that is a new license, stopping the infringement.
The more interesting question is whether there are any GPL-only interfaces used by Twin Peaks's filesystem code, whether wrapped or not. Since Twin Peaks doesn't release this code, it's harder to determine this. Plus, one then gets into who holds the copyright on that code, and if it's not Red Hat, they can't use it in their counter claims. I'm betting that someone would be willing to transfer their copyright to Red Hat in that case. This would make it infinitely more difficult for Twin Peaks to avoid an injunction, and make a settlement more likely. SFLC is on this aspect of the case, and hopefully others.