OK, the deal that I was just offered (as Platinum) is to stay 20 nights between 3/1 and 6/1 of this year and receive 30,000 bonus Marriott points.

I don't know if that is a standard, or if others will be offered different night requirements or bonuses.

Registration is required; award stays don't count, and you must be earning Marriott points (not airline miles) to receive this bonus.

Of course, it is on top of the points you would already accrue for your stays.