It is worth noting that the list DazzlaF1 links to represent the latest official entry list, released on November 30. On December 3, another press release was made, announcing that BMW Sauber's application to the 2010 F1 World Championship was successful. (See
http://www.fia.com/en-GB/mediacentre...ages/List.aspx for both of those) However, no full entry list has been released since then. So the list on the more fan-friendly part of the FIA website, that DazzlaF1 links to, actually represents the official entry list.
BMW Sauber have never been allocated any numbers, nor have they ever been on an actual entry list.