I had a similar dilemma a couple of months ago, wanted a change as i was bored of my current server and toons, so I started afresh on a new PVP server (GB ) .
I initially started with 3x Warlocks, levelled them to 20 and then moved over (server & faction change) a pally and priest (the transfers helped quite a bit, as I could bring over all the items I was lacking on the server (mats, gear & some gold). My levelling has been a mixture of the following

1-20 Questing
20-25 Shadowfang Keep
25-40 Scarlet Monastery
40-45 Zul Farrak
45-58 Scholomance
58-59 Outlands Questing
59-63 Ramparts
63-68 Sethekk Halls
68-74 Outlands Questing
74-80 will be a mixture of Instances, PVP and Questing

All instances have been done with a Ret Pally Boosting (3.9k GS) - to keep within the 12 minutes per level on some of the shorter ones I have been looting the big pull piles (handy source of income if you are not on an established server).

the main thing i have found is, that a fresh start on a new server gives you renewed interest in the game