Yes they do license both SBS for OEMSLP and keys are different for Standard and Essentials versions...
@ZaForD i did that with my Win 7 iso awhile back and had that thought about WHS2011 a few hours after i posted my last post on her. thanks for the link i lost the file i downloaded before.
No client restore iso with the Windows Small Business Server 2011 Essentials evaluation. If you can't boot from USB you are SOL to evaluate client restores.
HP aren't offering WHS 2011 (AFAIK) its Acer and Tranquil that have confirmed they are. Dell are offering SBS 2011 Std. SBS 2011 Ess. and WSSE for May delivery. I'm guessing that HP will be offering the same.