Even with the addition of a new tanking class, there are many occasions where players find themselves looking for a tank. With the great improvements to hybrid class' DPS, it's also been just as hard -- maybe even harder -- to find healers for groups. It's extremely common to see healing-capable classes spec for DPS like Retribution Paladins, Enhancement (or even Elemental) Shamans, and Balance or Feral Druids. The question then is if the option were available, would these players choose healing or tanking as another spec? It seems almost certain that players who can will spec either to tank or heal as their other spec in order to easier find accommodation in groups.
Are dual specs really the answer to the perceived tank or healer shortage? Ghostcrawler mentioned that the healer shortage was due to players not yet hitting 80 and were using leveling (i.e. DPS) builds. But now that more players are at max level, we still seem to see the same class roles being sought after in the public channels. The truth is, if players don't enjoy healing -- or tanking, for that matter -- they won't necessarily spec for it. Even if they did, they probably won't appreciate being pigeonholed into the role more often than they're allowed to play the spec they truly enjoy. While the new feature of Patch 3.1 will open up options for players, will it be enough?