We get a steady trickle of requests regarding changes to what receipts go out when someone signs up for a regular payment. We use an extension to help with this 'norecurreceipt'. The extension basically prevents the is_email_receipt from being set to ON on the civicrm_contribution_recur table - thus allowing the inital mail to go out but not the subsequent ones.
I discussed this some time ago with Dave & he suggested I post a blog to see where other people are at with recurring receipting.