Sadly, no.
The GIMP it’s nowhere close to Photoshop. I really hurts to say this, as I love Linux and Open Source/Free Software, but it would be a lie to say that the GIMP it’s as good as Photoshop… at least, if you’ve worked for a while with Photoshop and really know your stuff, working with the GIMP it’s not so easy, since there are a lot of things that are done in a different way. If you really are into it, you’ll probably get the same results with the GIMP, but you’ll have to learn and it’ll take more time.
On the other hand, you might want to think about what do you want from a graphics editor: if you’re going to use it for your work, then you should really get your hand in your pocket, take some money and pay for a professional tool like Photoshop; if you just want to mess around or design your own site, you may try the GIMP and learn with it.