[quote name='DarkNessBear']Yea, Spawn larva is pretty ridiculous. It's like having a barracks with 3 attached reactors. Is that really fair?[/QUOTE]
Comparing zerg to other races 'specials'... terran get both the fortress and comsat. Comsat costs 150, spawns with 50 energy, and gives the scanner AND mule options to the com center; mules generate 220 minerals in 30 seconds (I think it is) for 50 energy. Planetary fortress is a strong defensive weapon that can save your expand or base if you get attacked.
Protoss get chrono boost - which reduces build time on their units on all of their nexus for zero gas/mineral cost. The ability costs 25 energy. They additionally have the option to create a mothership, which gives invisibility, has good weaponry, has decent health, can cast vortex - which is amazing - and can call other units to it's location.
The zerg get queens and nydus worms. The queen costs 150, spawns with 25 energy, can spawn larvae for 25 energy, or expand creep for ... 10?. Queens have OK hit points, are mobile - though very slow off of creep. They have a STA and a ranged ground attack. It won't win battles, but may fight off a reaper or two.
All things considered, the queen isn't any more overpowered than the mule is for speeding up your economy or the chrono boost is for speeding up your build time.
There is still tweaking to be done.. perhaps on the spawn rates of the larvae, or the cost of the ability... but the ability itself isn't all that out of balance, in my opinion.