Interesting, it seem like a great addition. Only one thing: wouldn't be possible to get away with the 'viewtopic.php?pid=' part and use only the ids and pids? Like, instead of:
{{ForumLink|url=viewtopic.php?id=xxxxx|title=The topic title}}
It would be:
{{ForumLink|id=xxxxx|title=The topic title}}
This way it would be cleaner and more future-proof, since another forum software could perhaps not have the .php extension, or the page not be called viewtopic, or the id/pid be called directly after a slash — if that happened, then there would be thousands of viewtopic.php?id= to replace around the wiki. I see some problems that could arise when implementing it this way, such as dealing with the difference between ids and pids, but for me it seems like a nice improvement that is worth doing. (I may do some experiments "forking" the template to see if it really works better and then discuss the final result to decide what standard to follow.)
{{ForumLink|url=viewtopic.php?id=xxxxx|title=The topic title}}
It would be:
{{ForumLink|id=xxxxx|title=The topic title}}
This way it would be cleaner and more future-proof, since another forum software could perhaps not have the .php extension, or the page not be called viewtopic, or the id/pid be called directly after a slash — if that happened, then there would be thousands of viewtopic.php?id= to replace around the wiki. I see some problems that could arise when implementing it this way, such as dealing with the difference between ids and pids, but for me it seems like a nice improvement that is worth doing. (I may do some experiments "forking" the template to see if it really works better and then discuss the final result to decide what standard to follow.)