Thanks for all the replys!
I suppose a follow up question to this would be, if you were a newbie DM (like I would be) would you run RotRL or go for something simpler?
An interesting question from my perspective. 2nd and 3rd edition came out during a time I wasn't playing D&D (first wife saw it as competition, the relationship didn't last, got divorced, and so on). I started playing 3.5 in 2007, the same month that Runelords came out.. and it was my first DMing experience. Just as you're proposing.
Honestly, I think Runelords is a fine adventure Path. It will always be one of my favorites.
Having said that.. It's my belief that there are issues with it. Paizo was starting their product line. They'd just lost publication rights to Dragon and Dungeon Magazines. They needed to have Chapter One at Gencon. There was a strong need (and still is) to have the Adventure Path come out monthly for cash flow reasons. The author of Chapter Three was going through one ton of personal life issues when he wrote it. In brief, there are signs the were all under a lot of pressure and it was rushed.
Before anybody gathers up their torches and pitchforks, I'm going to say again- it will probably always be a favorite of mine.
But a first timer might not want to pick through the errata and debug it.
Salthorae, I might recommend you start with Council of Thieves, which is written specifically for the rule set, or Legacy of Fire.. which I think is the most polished of the 3.5 Adventure Paths. After that, perhaps Curse of the Crimson Throne.
Or, just start with some modules as Wicht suggested. It depends on how much you want to run an entire campaign.
EDIT: I'm running Runelords for the second time now, and halfway through Chapter Three (the second time).