there will be a newer revision for the coming G55 batch. The previous batch was S1095V, that comes only with a normal bag and they're currently out of stock and will be replaced with a newer revision. Which I forgot what code number already, but it'll come with an exclusive Targus ROG backpack and ROG mouse. Specs wise, they are the same.
1. no idea, never played guild wars 2 but i think it should be no problem maxing it out
2. i am also getting this for my cad applications like Revit, 3ds Max, Autocad, sketchup and along with photoshop/illustrator. I may give some opinion on this. Cad applications like autocad 3D could rely more towards the CPU. I'm not sure how much will the GPU be used. I've been researching about the performance of GTX660m gpu. And i'm still not sure whether 3D softwares are using more of CPU or GPU. But i could tell that the latest 3ds Max 2012/2013 has started to use the gpu to boost its performance. Maybe the same for autocad 2012/2013. However, the 660m may not be the best card to run your softwares smoothly (depending on the scene you're rendering, amount of objects etc) but it will do the job and definitely better than the other mainstream cards outside

3. G55 is 15.6" while the G75 is a 17". Both are huge in size, and bigger than any normal 17" laptops. Yes
both
Added on June 6, 2012, 2:09 pmwah dont la poison me..

eh no worth it la, same specs with G55 only

i found one with better one. Around the same price also. Contemplating now..

show me your spec.. or link pls..