I think far too many people have got hung up on the idea of SSD and what it can do. For the average user e.g. surfing the web, iTunes, office tasks, email and maybe the odd bit of photo editing then SSD adds little value to the computing experience. If you are a user that requires multiple applications running at the same time or video rendering etc. then SSD would be of value. Even then it does depend on how fast the machine is in the first place. A machine with low RAM slow entry level CPU etc. will not see much benefit in adding SSD whereas a user with "hot specs" will. I fall into the first camp i.e. average user, so my money would be better spent on RAM or a better monitor etc. Even boot times won't be blistering if the machine has low specs and for my money 15 seconds faster booting means little as I always use "sleep mode" anyway.
With respect, you're mistaken. Video rendering and multiple apps benefit from multi-core CPUs and extra RAM first, then an SsD. The MB Air was a success becsuse the SSD in that made up for the slow CPUs and low amount of RAM by making drive seek time (the true bottleneck in performance systems) a non-issue.
Too many SSD benchmarks focus on sustained data transfers - "Look ma, 400 meg a second!" when the thing that makes the difference to day-to-day users is opening and closing all those little files - random transfers. A good SSD will get random read / writes of 30 meg a second compared to about 8 or 10 from a hard disc. That's why an SSD will make a machine seem speedy even when attached by Firewire. No seek time, no whirring up the discs and no degradation of speed as the disc fills up.
Apple could do a lot worse than throw in their extra slim 64Gb SSD from the Macbook Air into a mini. The average user cares about how fast and snappy the machine feels rather than specs. An SSD could make the machine feel much faster without requiring any major overhaul.