From their press release:

Readers can now view selected NPG content on the DeepDyve platform. Access to a single article for a 24 hour period is available for $3.99

and

Thirty-day and annual subscriptions are available. For Nature, access via the iPhone app is available for $9.99 for 30 days or $79.99 a year. Access to the other titles is $8.99 for 30 days or $69.99 a year. Subscriptions are paid for through the iTunes store.

I have mixed feelings about this one. The pricing scheme is definitely lower than purchasing individual papers, but I usually want to keep a copy (pdf) of interesting papers I came across. A read-only 24hrs access should be $0.99. Makes me wonder how many institutions do not have access (understand: pay subscription) to the NPG journals. The other good news is the iPad app launch, coming soon. I wonder if they are going to take advantage of the tablet format, or if this is going to be a more or less straightforward interface of the NPG website. We’ll know soon enough.