I just ordered a new video card (ZOTAC GeForce GT 440 512MB GDDR5).
It's not all that great, but it was in my price range and should run Skyrim.

My processor is an Intel Core 2 Quad CPU Q8300 @ 2.50 GHz.

I was wondering how new meshes and high resolution textures will affect the gameplay?
Are they more taxing on the CPU or the GPU?

I would imagine that my PC's CPU can handle a little extra from the mods, but I have doubts that the video card would be able to handle anymore than vanilla.
Any thoughts?

Also, do you think a mod like http://skyrim.nexusmods.com/downloads/file.php?id=15123 will help me at all?

Mods effecting performance is entirely based on what they add and how they add it. Script heavy mods will demand more from your CPU, while graphics heavy mods will demand more from your GPU.

That being said, I can safely say you can skip the HD texture mods. Most other mods will be just fine.

I figured as much. lol. Thank you! I really appreciate it!