A Newsgator press release from last week reads

Subscription Synchronization

Users who subscribe to NewsGator Online Services can now synchronize their subscriptions across multiple machines. This is an industry first - NewsGator 2.0 for Outlook and NewsGator Online Services are the first commercially available tools to provide this capability in such a flexible manner. This sophisticated system ensures that subscriptions follow users wherever they go, users never have to read the same content twice (unless they choose to), and even supports multiple subscription lists so users can have separate, but overlapping, subscription lists at home and at the office.

Interesting. Synchronizing subscriptions for a news reader across multiple machines doesn't strike me as unprecedented functionality that Newsgator pioneered let alone an industry first. The first pass I've seen at doing this in public was Dave Winer's subscription harmonizer which seemed more of a prototype than an actual product expected to be used by regular users. I implemented and shipped the ability to synchronize subscriptions across multiple machines with RSS Bandit about 2 months ago. As for providing an aggregator that supports this feature and a commercial site that would host feeds synchronization information I believe Shrook has Newsgator beat by about a month if the website is to be believed (I don't have a Mac to test whether it actually works as advertised).

I find it unfortunate that it seems that we are headed for a world where multiple proprietary solutions and non-interoperable solutions exist for providing basic functionality that uses take for granted when it comes to other technologies like email. This was the impetus for starting work on Synchronization of Information Aggregators using Markup (SIAM) . Unfortunately between my day job, the girlfriend and trying to get another release of RSS Bandit out the door I haven't had time to brush up the spec and actually work on an implementation. It'll be a few weeks before I can truly focus on SIAM, hopefully it'll be worth waiting for and it'll gain some traction amongst aggregator developers.