According to Forrester Research [via CNET] the Zune Market Share (read awareness) is smaller than a rounding error for the poll:

When researchers asked MP3 player owners which one they bought most recently, the Zune was in second-to-last place, with only 2% of respondents naming it. Nearly everybody else–Toshiba (2%), iRiver (3%), Samsung (4%), Coby (4%), Creative (8%), Sandisk (11%), Sony (11%), and Apple (43%)–was ahead, with only Archos trailing.

Microsoft was even beaten by that Chinese power brand Coby, the maker of the $25 DVD player at Walmart.