"If he was still alive today, what would his music sound like? What, if any, soundtracks to movies would he have been interested in doing? Are there any artists/guitarists today that he would appreciate? "
In what musical direction would he have gone? Who knows? All we can do is guess. Some have said that Jimi was leaning towards Fusion jazz. He may have got involved in that whole Fusion jazz-era thing but I still believe he would not have strayed too far from his roots, and in the end, his music (had he lived) would still be heavily Blues-influenced.
Had he lived. a long-ago fantasy of mine was to have heard him jam, or in concert with (not necessarily all at once!), Robin Trower, Frank Marino, Randy Hansen, Eddie Van Halen, John McLaughlin (Mahavishnu-era), bassist Stanley Clarke, etc.
Also, it would've been very interesting to see what Jimi would've done during the Heavy Metal-era of the 1980s and the many lead guitar virtuosos it produced.
Man...it boggles the mind of what could've been.
I (do believe) and will say this: if Jimi were still with us, for sure he would've been a much mellower Hendrix, a la Clapton--a mere shell of his former Cream-era self.
Electrix
p.s. Oops, how forgetful of me. I left one extremely talented guitarist out whose initials just so happen to be S.R.V. Sorry Stevie...