I understand that having an 3rd aircraft is highly unlikely, but who knows what will happen 5, 10, 15 years down the line because you can only expand so much with the E190s and A320s. Unlike PE, jetBlue has their act together and also lacked the chaotic management team that PE has. jetBlue knows what market to enter and, unlike most other airlines, is willing to ditch a route before its to late (such as ATL). With that said, an larger aircraft would be nice to have a few years down the line to expand capacity at slot controled airports such as LGB. PSA, an sucessful low cost airline that was purchased by USAir was operating L1011 between Southern and Northern California and Pan Am was known to operate 747s between SFO and LAX. I think LGB - OAK is jetBlue's version of the popular SFO - LAX routes. Even having the A321 as the 3rd type of aircraft is not entirely out of the question as it could help with increasing capcity at airports like LGB.