Since you are specifically asking about PE and not about PR, I can't really comment, but had you asked about PR, I would say:
1. Lose the Xeon, get an i7 instead.
2. Lose the Quadro 600 and get a GTX 560+
3. Increase memory from 4 to 24 GB
4. Lose Dell as your supplier and either build yourself or get an ADK machine.
Look here what makes a good machine for PR CS5+: PPBM5 Benchmark
Premiere Elements currently (nobody knows about version 10) does not use nVidia CUDA technology for video work, so a less expensive ATI card with at least 512Meg of video memory will work fine
4Gig of ram with Win7 64bit does not leave much for PreEl... which is 32bit so it will use a max of 3Gig by itself... depending on motherboard type, up that ram to either 6Gig or 8Gig so Win7 leaves enough ram for PreEl to run
i7-990 vs i7-2600 http://forums.adobe.com/thread/854514?tstart=0
You could also consider an i7-2600k CPU (and the appropriate motherboard) with 16Gig of Ram
Building an i7-2600k computer
Google search site:forums.adobe.com 2600k
... and many more