HMRC are not issuing a paper Employer Pack this year.

Instead HMRC have published important information on their website which includes:

the latest edition of the Employer Bulletin (issue 37)
the Basic PAYE Tools (formally the Employer CD-ROM)
how to finish your payroll for 2010-11, and
start your payroll for 2011 -12 by using helpsheet P9X (2011) Tax codes to use from 6 April 2011.

HMRC PAYE Year End