This might help...
I had a 4 year old sony viao that ran DW, & PhotoShop with a 1.86ghz pen. M processor, 1GB ram, a 100GB hard drive at who knows what speed, and I don't know my graphics card... (I still have it lol)
Anyway, it ran them for the most just fine. I did have some speed issues that I def. Noticed but never had any majors problems. 4 years and still on the original hard drive, never upgraded ram or anything.
I think you'll be just fine until you start having to save a ton of images, vidoes etc...then you might run into a few speed and storage issues I think.