Is it time to upgrade?

Okay so I built a PC about 2 years ago and put in an nVidia GTS 250 graphics card. It's performed very well for the past couple of years, and can run many of my games on max settings. However, new GPUs come out like every month, and 2 years is a lifetime for some cards. So, is it time for me to upgrade? I feel like if I make the jump to the GTX 480 or 500 series cards, there will be a discernible difference.
 
Can anyone shed some light on my predicament?

What games do you usually play and what is your budget? You can always get newer and better cards, it just depends on your situation whether you actually should. The GTS 250 would be considered a low-end card for today's games, but if you play mostly casual or Source games for instance you don't necessarily need to upgrade.

I have 8800 GTS 512s in SLI which by themselves is about the same as yours. I believe unless you are having to lower your graphics to Low or most of the games you are running are struggling to play (I have had no problems so far with all the games that are out) then you dont NEED to upgrade. That being said, if you have the money to throw at a new video card then go for it, but just remember if you are getting a 480 - 500 series you have to look at the rest of your specs such as CPU, Memory, Motherboard and your power supply (the new cards use up a lot of power) to see if there might be a bottleneck somewhere else in your computer and just making your card not run as fast as it could. (I'm not saying there won't be a difference you just might not get your moneys worth.)

@Nikral:

I recently purchased a GTS450. It's basically twice as powerful as my old 9800GTX. Now I can run BC2 on max settings and a smooth frame rate. It only cost me €120. Those new GTX cards look pretty sweet, but they're not worth the 400-500 if you ask me. Unless, you are absolutely determined to play Crisis 2 on max on the day it comes out.

According to Norman Chan, this may be a good upgrade:  http://www.tested.com/news/tested-nvidia-geforce-gtx-560-ti-video-card/1700/ 
 
He talks about it a bit on one of the podcasts. It's like 2-3 weeks back I think. I think Jeff's on that episode btw.

Ask yourself this: Are you happy with the performance you are getting? If so, then you can hold off from upgrading and save yourself some coin.  
 
If you are not satisfied or noticing there is a significant dip in the performance you are after with new games, then upgrade.  

Ask yourself this: Are you happy with the performance you are getting? If so, then you can hold off from upgrading and save yourself some coin.  
 
If you are not satisfied or noticing there is a significant dip in the performance you are after with new games, then upgrade.  

Of course there will be a major performance leap if you go from the 250 GTS to a 480 GTX, especially if you have the 512mb version. The 250 GTS is a budget card and the 480 GTX is a performance card. But how is the rest of the computer looking? The 250 GTS to 480 GTX is not only a massive leap in performance, but will most certainly bottleneck your computer if the rest was picked to work with a 250 GTS. Lately we've had a lot posts regarding PSU problems for example. Which PSU do you have? Nvidia cards tend to get hot so proper cooling is essential if you haven't invested much in that.
 
If you post your specs we could probably find a good card for you. $200-250 is actually a lot of money for a graphics card and you might be better off saving those bucks and do a proper upgrade with new motherboard, CPU, PSU and memory.

Your going to be bottlenecked by your meager processor no matter what you upgrade your card to. It's not going to get the intended framerates with a dual core for certain games. For the price a gtx 560 is the best choice, but your going to be severly bottlenecked unless you use something that's a quad core and not that slow either.

^^^truth.  A new CPU will hugely improve your system--more than a new GPU would.