Leica is offering mail-in rebates on selected M-Lenses (May 1 till June 30, 2009):
$5,000 and more and get $500 back (mail-in rebate)
$4,000 to $4,999 and get $400 back (mail-in rebate)
$3,000 to $3,999 and get $300 back (mail-in rebate)
$1,000 to $2,999 and get $200 back (mail-in rebate)
(Source)
Leica M8 upgrade rebates:
Leica Camera Inc. will offer customers who buy a brand new M8 from an authorized Leica dealer a 50% discount on an M8 upgrade consisting of the shutter, sapphire glass and rangefinder mask. This promotion runs from April 1, 2009 to June 30, 2009. Customers will have 30 days from the date of purchase to send in the M8 for the upgrades (source).