Any computer you buy now which isn't a low-powered netbook will be more than fast enough for anything most normal users need to do. Here's some info which hopefully you'll fine useful. I've also written a more extensive blog post specifically targeted at college students looking for a new computer. It's a couple months old, but mostly still relevant, and has some specific machine recommendations.
Even the previous generation of mobile processors, the Core 2 Duo series, will run Office, Photoshop, Visual Studio and most video games without any trouble. Any of the 2010 Core processors, even a Core i3, will beat a previous-generation Core 2 processor at just about anything, and again, is more than sufficient. Most laptop users' processors, even superusers, run idle most of the time. You will likely be just fine with a Core 2 Duo; just make sure you get a newer one with the 45nm technology. I would advise at least 2.0 GHz, though slower can work. You can check a given processor's specs using Intel's specfinder.
Memory is going to depend entirely on how you use your computer. Most people will get by just fine with 2 GB. If you use memory-intensive applications a lot though, such as Visual Studio or Adobe Creative Suite products, which you said you do, you'll get by with 2 but would probably run more comfortably with 4 GB. It's a subjective matter, but more than 4 GB is probably overkill unless you run multiple VMs simultaneously.
Graphics are a tricky situation. Intel's current-gen HD integrated graphics, which come with any Core ix processor, can handle most games on medium settings. If it'l run on a P4-era computer, it'll run on this. You'll probably be fine with integrated graphics, but the extra boost from a dedicated card can be nice at times. If you want dedicated graphics, look for switchable graphics like Nvidia Optimus, which allow you to use the integrated GPU to save battery, and switches to the dedicated GPU only when required, like for games. If you do get a Core 2 series processor, a dedicated GPU might be more necessary; check what graphics chipset is in the computer you're looking at. If it doesn't meet the specs for the games you play, your money might be better sent on upgrading to a Core i3 with the newer integrated HD graphics rather than spending it on an older, more power hungry dedicated card.
Hard drives are an oft-overlooked bottleneck. Size isn't a huge deal, you can figure out for yourself how big of a hard drive you need, but speed matters. Get a 7200 RPM drive; I would choose a 320 GB 7200 RPM drive over a 1 TB 5400 RPM drive any day.
Another thing to consider with hard drives is having an eSATA or USB 3.0 port for fast backups. Backups are very important, and having a fast connection to an external drive makes backing up a much easier experience, thus making it more likely that you'll do it often. This was a critical part of my decision on what laptop to get.
To sum it all up...
As long as you don't buy a netbook, basically any computer buy now will be plenty fast for your needs. Read some online reviews, and see if it's a good laptop overall, don't just worry about the specs; they'll probably be fine.