Jim Callis has some more draft details at Baseball America:

-The draft has been reduced from 50 to 40 rounds. Most of the 41-50 picks are used on organizational players, or go towards prep players who aren’t willing to sign.

-Any attempt to circumvent the draft cap is “expressly prohibited”.  That ends any chance of signing a player to an under-the-table deal which would pay the player more after the draft.

-Callis clarifies that even though a team loses the cap value of a player if he goes unsigned, the team still keeps the difference between the bonus and the value if the player is signed to a below slot price.

-If a player fails a physical, and the team fails to offer him 40 percent of his slot value, the player becomes a free agent.  The team’s draft cap would be reduced by his slot value.

-The 2012 deadline will be on July 13th.  The deadline has been moved from midnight to 5:00 PM EST.

-Here’s some good news.  Teams can announce signings as they happen, rather than waiting for MLB to sign off on the move.  MLB removed their draft-support program, which was used to strong-arm teams into delaying over-slot announcements.  The Pirates have lost a few over-slot players because of this, including Dace Kime in 2009.

-Lottery picks can be traded, but can only be traded during the season, and not in the off-season.  Picks can only be traded by the team who originally had the pick.

-Teams get an extra year of protection for not signing a pick in the first three rounds.  A team used to get a compensation pick the following year, but it was unprotected, meaning they had to sign that player or get no further compensation.  The compensation pick in year two will now be protected.

-Teams no longer have to tender a contract within 15 days of the draft.