They replaced the bonus from Herbalism with something usable and potentially attractive. Rather than putting a short HoT on you, the herbalism bonus now grants you haste rating for 20 seconds once every 2 minutes. So it gives you an extra cooldown to punch, off the GCD. It still heals you for a nominal amount, but aside from soloing I can't see that mattering too much.
But there is a problem coming for profession perks in general, one that will make the former problem of herbalism not having a useful one for raiding seem minor. The issue is that different professions give you different options for what bonus stats you get. Every profession gives you approximately the same amount of bonus stats (or at least they are supposed to) but some give you one particular stat while others let you choose between stats.
Given the relative power of Strength, Agility and Intellect in cataclysm, professions that let you choose one of these stats will be far more powerful than professions that give you something like crit rating or haste rating. Using a parse of an old combat log, it appears that as things stand right now, haste rating is about 81% as good as Intellect for throughput, crit rating comes it at 28% (or practically useless). At the same time, Intellect is almost twice as good as Spirit for mana over a nine minute boss fight. It's more like 130% better if we drop it to five minutes.
Being more than twice as good as the other mana stat and around 25% better than the next best throughput stat at the same time means that getting 80 bonus points of something other than Intellect will always be far inferior to getting 80 bonus points of intellect. Since other classes are going to have similar relationships with Agility and Strength, I expect this means we will be seeing an awful lot of leatherworkers at max level in Cataclysm. Why leatherworking? Leatherworking not only allows give you the bonus 80 stat points in the form of an improved wrist enchant, but it allows you to replace the wrist enchant you would otherwise have taken with the stat you actually want. Sure, the maximum level bracer enchants give 65 haste or critical strike rating, and that is only replaced by 50 intellect, but in the healing priest example, 50 intellect is only barely behind 80 haste for throughput, and it has significant mana benefits as well, making it a fairly clear choice. For most dps classes I expect the 50 Strength, Agility or Intellect to simply be better than 65 of a rating.
This is just another case of how stat imbalance leads to problems. The conversion rates for ratings need another look to make sure we are interested in more than just one stat.