hhm... the arrival of the lightning ninjas seems to happen about 30% only... since they are searching for sasuke's team and i guess they already knew the place... but i think the hokage... while resting sent messages to all allies... XD
I am really hoping that sasuke would go to Konoha and help the obliterate pain.. but I KNOW IT WONT GONNA HAPPEN.. about 2% only

(
as for gaara's arrival.. it would be difficult to say that its possible since he is the kazekage over there.. It had been stated in the early episodes that a kage will have a hard time going outside the village... and i guess gaara would protect the village before his friend... XD gomen to say about this..
or how about this... Kakashi will be there to save naruto? hmm... Kakashi had been gone long for many episodes!!!!
or simply.. NARUTO will surprise us again