We know about this issue and plan to have it corrected in time for launch. All class abilities will work as normal in rated battlegrounds. Consumables and engineering items will still be restricted, just like arenas.
Not being able to post on those Cataclysm forums I was Wondering 'Why are Rated Battlegrounds being subject to the same restrictions as Arena's?'
The gameplay philosophy and realities of Bg's and Arena's are quite different; where the Objective of Battlegrounds are either to secure/defend a resource, the objective of an Arena is to eliminate the opposing team as quickly and efficiently as possible with minimal damage taken. This basic philosophy is seen even in the terrain of BG's; choke points in Alterac valley, and deliciously tempting tall cliffs with long falls in Arathi Basin and Eye of The Storm. It is also seen in Arena's where the maps are firmly tuned to giving no advantage to either party.
Within the parameters of Arena's the restrictions of Consumables and certain Profession abilities makes absolute sense; the gameplay is fast, unforgiving and resurrection is impossible. This is not the case in Battlegrounds where the time of conflict is much longer, there is a greater forgiveness of player error and frequent resurrections are guaranteed.
Along with this, to have only certain Profession abilities singled out for Rated Battlegrounds based on the history of restricted use in Arena's is unacceptable, a violation of the Design Philosophy. In strict observance of Mumper's post, no restrictions would be placed on the passive and active benefits provided by Harbalists Lifeblood, Tailors 3 second root nets or Stats gained by Jewelers/Miners/Skinners/Enchanters and Blacksmiths.
By way of comparison; Lifeblood grants an initial heal in addition to 240 haste for 20 seconds, Engineering's Hyperspeed Accelerators grant 240 haste rating for 12 seconds, while both can be purged, the Herbalist has already benefited from the initial heal.
Nitro-Boots have a 5 second duration at 300% speed, Rogue has an 8 second Sprint (Glyphed to 100% speed) and Feral druid's Dash has a 15 second 70% speed (Glyphed to 90%). On level ground the Glyphed Rogue is 25 yards ahead, while the Glyphed Feral Druid is more than 45 yards ahead. The Nitro Boots are not an unfair advantage.
Mind Amplification Dish has a chance to MC the victim for up to 10 secs with a 10 min CD. Priests can Mind Control a target 2.5 sec cast, effects last up to a minute, with no cooldown
Parachute cloak enchants have a 1 min CD, while Mages Slow Fall and Priest's Levitate have no cooldown. In a situational use experiment, the Engineer, Priest and Mage are Typhooned off of the Lumbermill, all use their slowfall/Levitate/Parachute but a Hunter Multishots them all. Only the Engineer dies.
Engineer's Explosives already have a CD and are of situational use, if necessary increase these cooldowns, but do not bar Engineers from a unique ability.
Consumables are of use to every player wishing to participate in all aspects of WOW, though Alchemists receive an additional 40% benefit. Restricting situational use consumables in Rated Battlegrounds severely prohibits exceptional or well practiced players from distinguishing themselves, it does not fix an nonexistent advantage over any other player.
A well timed Waterwalking potion to get from Blacksmith to Stables for the cap/defend, a Free Action Potion used by a Warlock or Shadow Priest who was just locked out of their spell trees, a Potion of Speed used in place of Bloodlust/Timewarp/Lifeblood/Hyperspeed,Purification Potions used by classes that would otherwise not have that ability, those are not an unfair advantage over another player.
Those are the types of items, abilities and situational awareness usage that serious Raid Leaders would EXPECT from the raid team, and what the members should expect from themselves. That mentality will be used and brought to the Rated Battle system with the inclusion of additional Guild Rewards from the majority of the BG being guild members, do not hinder the Guild or the Individual by restricting the use of items or profession abilities that can be purchased or crafted by EVERY player that has the drive to obtain them.
(rant, I know, but I'm passionate)