A little update here:
I'm currenty using my brand new Inspiron 15, running Mint (Gloria).
Due to pricing anamolies I actually ended up getting a MS Vista system from a local retailer. That is to say, it was actually cheaper for me to get this machine locally than to order the Dell Inspiron 15n.
I'm pleased to report that I've successfully partitioned this machine (Vista still exists on this hard drive somewhere
...and everything I use it for works with no meddling on my behalf. The only issue, which is echoed on the Ubuntu forums is the sound is a little timid, but can be sort of amplified via software tweaks.
That said I'm glad to have purchased a new retail Dell machine and 1.5 hours later I've got a nice dual booting Mint installation!