Yup, it's time for a boost for sure, particularly if you plan on doing any WvW or many of the open world random events.
Can you upgrade your system? In some ways, yes, but you may still be leaving yourself hamstrung by doing so. I don't know that your system can handle any of the newer Intel CPU's (the i3/5/7 series), and an Intel chip is likely what you'd be looking to buy for that mainboard. So your CPU is limited, and due to the age of your system you wouldn't be able to access the data transfer speed that is available via a SATA 3 port for your hard disk. As a side note to this, you also wouldn't have any USB 3 ports which are also significantly faster than what you currently have. Unless you're playing from a jump drive or external disk then this wouldn't impact your gaming, but it's worth noting.
Memory could probably be bumped up easily and cheaply. Having more memory doesn't necessarily automatically make gameplay faster, particularly if the game is only 32-bit (which most of them still are), however it will make a difference if you have multiple other programs/resource hogs running in the background. In modern systems I wouldn't consider anything less than 4gb, and I prefer 8 or more just because I'm stupid.
Your video card needs help. Badly. While you may have purchased the card 4 years ago, that chipset is at least 6 years old and will perform accordingly. You can probably find an upgrade to it for relatively low funds, however you might be hamstrung yet again by the type of slot it's in.
One other item you didn't mention is your hard drive. HD's are usually waranteed for three years, and once you start approaching six years they tend to be on borrowed time (in my experience). Besides age, data transfer rate can come into play for things like loading screens when jumping zones. Getting a SATA3 drive and pairing it with a SATA3-capable board can help this - and help even more if it's a SSD!
In short, there are some ways you can probably upgrade your system, but you would be doing so knowing that you are still limiting yourself in the long run. In my opinion, I would just get a new computer. Upgrading the old one would be throwing good money at a not great situation. A new gaming computer capable of playing GW2 decently can be had for less than $800 (here is just one example... http://www.newegg.com/Product/Product.aspx?Item=N82E16883227408). You can also do it yourself for around the same price, give or take $100.
For my money, the AMD Radeon 6850 is one of the best values out there for graphics. Not the best performing, obviously, but you get a pretty damn good bang for your buck with that card (it's what I happen to be running right now). Tom's Hardware and Passmark are good hardware resources for research on components, performance, and value for the dollar.
Anywho, my $.02. See you in game!
» Edited on: 2012-08-02 18:32:36