I think for Deccan, they are almost out of it. Got to win all 5 games from now to make it to the semis. And they face Bangalore in their home ground next, which is a hard place with the huge crowd support and a strong RCB team.
The fourth semis spot could be fought between RR, CSK and KKR. If RCB dont maintain a consistent run and win 3 more out of 5, they could end up letting two of the above three teams get in. Its still quite open for 7 teams to make the final four.