I would recommend the SSD as it greatly increases boot times and overall usefulness: I put SSDs in my ancient netbook (with a poor SATAII implementation) and my old macbook pro (with only SATA I) and they are like new machines. The responsiveness is amazing, waiting for programs to load on windows startup or after clicking an icon to initiate them is a thing of the past. Before the SSD the netbook was unusable for over a minute after log-in and the macbook took almost as long. Now the netbook is ready to rock in under 10 seconds after login and the macbook is so speedy (both in Win7 & OSx) that I can't really time it. The SSD should also load your video files much faster, though depending on what your editing program of choice keeps in RAM (and how much RAM you have) the benefits of this might not be Earth-shatteringly astounding. They'll still be astounding though, especially if you pick up that Samsung 840 Pro
I agree with the previous poster that when it comes to loading bottlenecks the slower-than-slow HDD is the #1 suspect, especially on Windows startup. Also a laptop HDD is easier to upgrade than its processor.