Piper Jaffray analyst Gene Munster says in a note to clients — as reported by “Fortune” (http://macte.ch/dgHHO) — that the iPad 2 is apparently totally sold out — and that 70% of the units were sold to new buyers.

The analysts estimates that 400,000 to 500,000 iPad 2s have been sold, compared with 300,000 of the original iPads in its first weekend on sale last year. The difference is that nearly all those iPad 2s were sold in one day; stocks were essentially depleted by Saturday and not replenished.

Munster says 70% of iPad 2 buyers were new to the iPad, compared with 23% of iPhone 4 buyers who were new to the iPhone at launch. His studies show that buyers were split almost evenly between Mac and PC users (51%/49%). By contrast, the split for the original iPad was 74%/26%.