I agree that the limitations on casting make most PvP bard templates worthless. I'm actually not too mad about this. Last thing I want to see is for bards to become the PvP template de jour. I actually like it that a lot of people are still amazed by the unique and mystical powers of provoke, discord & peace (although I hate peace myself). I'd hate it if loud-mouthed PvPers started screaming incessantly over general chat about their bard skill...yuck.
I would, however, like to see some additional PvP capabilities for my current bard templates, in case I get raided at a spawn. I've been thinking about some tactics that might be useful after they correct the casting limitations for my current bard characters - I'm not gonna build a PvP specific bard ever.
Discord/Tamer - I've had this template for a long time, but rarely go to spawns on this character any more because I hate being on foot in felucca (yeah I have dreads and cus, but you really need a GD to be effective at spawns). Raiders see people on foot as sitting ducks, and like to take out tamers first because that will put their pets out of commission as well. Since I've got discord on this character, I think some combination of despair/all kill/paralyze/curse/poison might work very nice. Might not be enough to kill a mounted, well equipped PvPer, but should be enough to make people want to stay away. Curse/Tribulation/all kill/flamestrike might be a very nice pile of damage. Will have to test it out once casting is allowed.
Bard/Mage (provoke/discord/music/magery/med/eval) - Only good thing about this template is that it's already set up with a huge mana pool & mana regen. There's nothing that this character can do straight up in PvP, but in a group field fight I think this can be a good finisher. Biggest problem in a field fight a lot of the time is that it's tough to finish people off before they run off screen. It's tough for spellcasters, because of casting delay, to chase people down to get that last shot it. I think with proper timing, I can use my bard mage as a closer. What I'm imagining is I'll keep an eye on the archers & mages as they fight, and if I spot one of my team getting an advantage, I'll cue up flamestrike & despair. If the target gets below 1/2 or 1/3 life, slap on the flamestirke & and despair and try to stay within range of the guy for enough ticks for him to die. Again, this is not usefull in straight up PvP, but this type of effectiveness can be useful when you get raided (as opposed to just being a sitting duck bard).
Bard/Archer - My bard/acher is largely an ABC archer. I'm able to dance with most other templates in PvP, but not able to finish them off because my template isn't optimally set up for killing others. What happens is that either I or my opponent will get the advantage, then the other will run off screen (I'm thinking of situations where we get raided at spawns, not straight up PvP). I think with proper timing, a combination of despair & moving shot can be enough to close the deal in some of these situation. Biggest problem is the mana cost. This template relies on leeching mana (which isn't effective in PvP) so doesn't have a huge mana pool or a lot of regen. So, will only be able to keep despair up for like 4-6 seconds. If it's going to work, it's gotta be well timed.
Those are my ideas, would be interested to hear others. Not that interested, actually, in bard-based pure pvp templates. But some ideas about how bards can be used when getting raided would be awesome.