I still don't like the Jetbikes even with their points decrease. The offense is still a tad weak. Go ahead and buy them though, the models ain't changing.
Avengers are coming out with new models so you might want to hold off until then.
Serpents are always good, I mean what else are you going to transport your Scorpions, Banshees, and etc in that has a 12 model capacity? (I think this is still a rumour, but still...)
Like others have said fill out your Warp Spider squad, get a Wave Serpent and if you want, the new rangers.