I've heard conflicting things about the engine naming as well, though this article (which sounds like it was cribbed from a BMWAG press release) refers to all prior engines by familiar names and the new designation for the new engine.
N62 is definitely not correct, since a N62B30 would be a 3.0l V8. I was thinking N58, since M56 is the latest M50-line engine, and odd-numbered engines are all diesels.
The new engine will debut in the E90 3er and 6cyl versions of the E63, and I'm sure will make its way into all other product lines save E65/66 in a couple of years.
2001 325i Touring Alpinweiss/Anthracite cloth, Alpina Softline
1988 M6 Royalblau/Silbergrau Nappa