A link to the contributions page is much more useful in case of vandals, which is what the rollback button is supposed to be used for.
Yeah. I'm not speaking to anyone in particular when I say this next bit, but let us not forget that rollback was never intended to be used for reverting good faith edits, which unfortunately is what some people use it for. It wasn't supposed to be that way, since that's what the undo button is for.
The MediaWiki:Revertpage change is live now - it was updated to match the version used on Wikipedia. This is the updated code it uses:
Reverted edits by [[Special:Contributions/$2|$2]] ([[User talk:$2|talk]]) to last version by $1
This may be awkward for those wikis that have customised their revert summaries, since now they won't be able to trim their summaries down without deleting the system message, which some wikis do not fancy doing.