Just been leveling Nitrodax; she hit 45. I'm also dreading getting her Enchanting to 300 - it's at 230 right now.
Still haven't quested in Northrend, but at least I can spell it now.
I'm pretty sure I'll be playing Nitro right up to 60 and then start the foray into Northrend with my other toons. Of course, her primary professions have to be up to at least 300.
....and all these little guidelines that I'm making for myself might just get thrown out the window. I reckon we'll just have to see how it goes.