Windows 7 will boot faster, Photoshop and Visual Studio will load faster.
(Opening Photoshop - SSD = 9 seconds vs HDD = 16 seconds)
Visual Studio performance while running won't be much changed and compile times probably won't improve. Photoshop notes from CG Society forum
A SSD won't improve your typing accuracy and speed, or improve your ability to run a program efficiently and that is where we spend the bulk of our time setting up the programs and manipulating the data to finish a job.
Have you already gone from 6GB to 12GB of RAM on your workstation? That might be the best use of ~$200.
As fast as SSDs are they're not nearly as fast as programs and data already loaded in RAM (SuperFetch).
Superfetch learns what programs and data you work with on a regular basis. Based on experiance watching you run your computer SuperFech will pre-load programs, helper files and data into RAM just on the chance you're about to start working.
Some people will say this is the reason Windows 7 gets a bad rap for using too much RAM. But if you're not using RAM it's being wasted.Background on SuperFetch