You’re confusing a shelf registration, which essentially signals intent to sell up to X number of new shares, with the actual registration of shares previously issued but not registered, which is nearly always an explicit requirement to occur within a certain period of time, codified by language in the agreements governing issuance and sale of specific unregistered shares that would have been previously “announced” in a shelf registration.
There is no new dilution, though shares will be added to the publicly traded float. Please simply refer to Bored Lawyer’s earlier response. He’s, well, a lawyer who happens to deal with this stuff.