Cryptic and Perfect World have patched in a significant update to Champions Online's alert system. For starters, rewards for Grab and Smash alerts have been swapped. Grabs now give XP while Smashes grant resources and a resource buff. Grab alerts will also require a level 10 character going forward, while Smashes will require a level 20 toon. This was done to prevent low-level XP seekers from signing up for something they likely won't survive.
The devs have also tweaked Champions' queue structure so that "there will always be one Grab, one Burst, and one Smash available at a time." Click through the links below for more info.