Thanks bjc. What I've been trying to determine is if there are any H/W bottlenecks. From the information provided I can not see any. Still to be determined is the speed of your HD 5400rpm is the low end of what's common , but 7200rpm is desired. This should be listed in the specs that came with the HD/computer.
What's left is the interesting point that Jim Wilde has brought up. If you have just recently started shooting RAW then the time spent in ACR has to be factored in If you have always shot RAW then there is nothing new here. Another could be the number of images that come off of the card. If before, you were shooting fewer phptps before import, it could just seem longer.
Based upon your current settings, I would make the following recommendation: Increase your ACR Cache to 30-50GB. You have lots of free space and while it won't improve import performance, it will meand that LR will need to revisit ACR less often to regenerate image data.
Somethings your might consider if yo have multiple drives would be to segregate your ACR Cache, Catalog and master files onto separate drives. They may be competing with each other fro R/W time on the one HD. This is not a remedy that should be required and any improvement would be slight.
One other thing that you can do . LR is a multi threaded, multitasking application. LR can continue to import iamges as a background task while you move on to your workflow step 2 as soon as the first image appears in the "Previous Import" collection. My workflow begins: Import, Cull, Assign additional Keywords, titles and Captions... I begin reviewing images for rejects and picks as soon as I have an image to work with. I can't even tell you how long it take to import a 16GB card full of 25Mb DNG images.
Speaking of DNG, (My camera writes DNGs btw) Are you also converting CR2s to DNG on Import? If so, Why? Also are you taking advantage of LRs option to make a temporary second copy to another drive on import? Have you always had this option checked or unchecked?