If the CDN is on Comcast’s premises, or primarily feeds a single last-mile network (which would de facto be true on a local level), then same.
A CDN doesn't carry traffic at all; it hosts content (multiple copies of it in different locations) for others to carry.
http://en.wikipedia.org/wiki/Content_delivery_network
CDNs operate servers, not routers. The servers can be located in data centers with easy connections to ISPs and transit providers, but their traffic still doesn't get privileged over other traffic coming in to the networks of those ISPs and transit providers. There are no separate routes that CDN traffic takes to a user's computer, that other traffic from sources in the same data center, or going through routers in the same data center, can't take.
I'm focusing on the functionality that's being implemented, which is what the poster I was responding to said was important. Having privileged routes is different functionality from having multiple hosts that all have copies of the same data.
> a CDN effectively carries traffic from a content provider to the end user.
But so does a non-CDN. So does any route on the Internet. The only difference with a CDN is that the content provider has paid for more servers to host multiple copies of the data. But the money is for those multiple copies, not for giving any specific copy a privileged route to certain users. As above, that's a functional difference.
Here's another way of seeing the functional difference. Say I use two online services, A and B. A is served using a global CDN. B is served using a privileged network with my current ISP. Now I change ISPs to one that service B isn't paying for privileged access to. I see no difference in performance with service A, but a big difference in performance with service B. So service A using a CDN doesn't lock me in to a specific ISP; but service B paying for privileged routes does.
> the end result is still "pay more for faster access"
No, it's "pay more for multiple copies of your data". It's not "pay more to have your data go over a quicker route from the same place".
> isn't that exactly what net neutrality is against?
No, net neutrality is not against "pay more for faster access", like service A above. It's against "pay more for privileged access to an ISP's users", like service B above.