To get a LOT of people interested in aikido, all you need is someone who can pull off a distinct aikido technique in the UFC. One kotegaeshi, nikyo, sankyo or whatever and you would hear Joe Rogan screaming AIKIDO!
Judo is still relatively rare in the UFC but guys/gals like Karo Parisyan and Ronda Rousey have made it work . I predict aikido will make an appearance one of these days. Just waiting for the "chosen" one...
The problem though is that small joint locks are illegal in MMA rules - so no wrist locks or finger locks. The taping of the wrist/hand inside the gloves also makes it extremely difficult to apply. I can see something like a variation of iriminage being used but it might be mistaken for Judo.
Even if Aikido were used in the UFC, it won't create a renaissance in Aikido because of Aikido's philosophy. MMA fans just wouldn't have the patience to practice it without hard sparring. Similarly there is very little obvious Aikido techniques that can be amalgamated into an MMA gym. Alot of people go straight into MMA without coming from a traditional martial art or single discipline background.
Judo is far easier to amalgamate into MMA because MMA has a strong grappling base in collegiate wrestling. Judo is effectively an alternative to wrestling.
I would love to see Seagal go back to his roots; out of interest which Seagal film do people think is best for Aikido?