It really depends on what the OP is willing to "sacrifice" in the meantime. The GPU will undoubtedly be an upgrade over current specs(650M with 1GB of GDDR5), when the haswell update comes.Keep in mind that Haswell will be of most benefit to devices with low-voltage CPU's (like the Macbook Air). It's not really going to be much of a performance difference, except for the integrated GPU.
The system you've spec'd out is going to be quite snappy for several years!
So if the OP can "survive" with what they have now, then wait. If the OP is holding off jumping into something new(adobe cs6 for web developing) then there is no need to wait.
The OP needs to ask him/herself - If I bought the iPad3, would I have been pissed when the iPad4 was announced? IF the answer is YES!!! then wait, if the answer is "I don't care", then buy now.
There will always be something better around the corner.