Tasting can still be done but it will only work for registrars with a high number of kept registrations.
Don't quote me on this, it's been a while since I read up on registrar tasting requirements, but I think if less than %5 of domain registrations are deleted (for any given month), the fee is completely refunded (no tasting fee). So, big registrars (like Godaddy, Moniker, Enom, etc) can still do it.
However, note that this was not designed for tasting but for deleting accidental and fraudulent registrations (stolen credit cards, etc).
As far as other registrars or using your registrar (if you are accredited), you can still do it, but there is a "restocking" fee. I think the registry charges ~$0.xx for each registration that resulted in a deletion.