I just sprang for the “pro” version of Remember The Milk, entirely so I could get the native iPhone app. It’s $25 per year, and I wonder if there’s any other examples of iPhone apps which are effectively subscriptions. $25 a year also seems a little steep for another interface to a database which they maintain for free.
The other thing that struck me, as I reloaded the main RTM page, is that they still brand themselves as “beta”. I know that we’re in the age of the perpetual beta, thanks to Google, but last I checked, I wasn’t paying for those Google betas.