I see the following effects of exclusive drops:
- registrar connections will become less valuable; many ICANN-accredited registrars (who probably depend in large part on revenue from these) will go bankrupt
- lower auction closing prices; its difficult to monitor several auction venues, rather than just the 3 or 4 drop gorillas we were used to, so on average there will be less end-users and/or big-budget domainers watching the drops
- large domain registration resellers getting in on the action by changing their TOS to allow repossession of expired domains
- eventually, even small domain registration resellers will try the same, and the situation will become so complex and intolerable that ICANN will get its head out of its *ss and start doing its job by disallowing exclusive drops
Just my 2c.