It might be best to upgrade to get the "full effect" with all the new higher polygon models and such. The video card won't definitely cut the mustard, if I recall correctly you need at least 512mb on the video card.
The discussion for gaming rigs and how to build them is massive. Theres no less than 200 million websites and articles. I point out this one because its more recent: http://www.hardware-revolution.com/500-gaming-computer-2/
The article links to other theories and builds that might be useful to you. I hate the new idea of a whole new PC or laptop, but I want to get the full effect. I don't need 3D but I want to play smoothly at 1900x1200 with anti-aliasing on.
I'm going to warn you Dalmat, don't take my advice...
But if I were you I would just sell the laptop, re-invest the money into a newer gaming rig and score the parts you need. From what I understand the game will be processor intensive so you want speed. Most people buy a slow quad core because its a quad but frankly most software hasn't and doesn't support multi-core processors. FFXIV doesn't either :(
I'm think about going this way myself:
i9 CPU (a few of them can overclock to 4 Ghz on air)
Nvidia 460 videocard
1 80 gig SSD (solid state drive) for Win7 and FFXIV
bare minimum 2 or 4 Gig DDR3 ram (upgrade later)
everyone has different needs so what I need might be different from what you need. I know I just want the full effect.