The lower daily goals are kind of lame and could use some spicing up.
Maybe make some of them goals like win 3 in a row, or play a deck based on color, maybe do like double kill in a turn, I can come up with more if needed, though I'm surprised wizards haven't thought about it...
Here though the biggest suggestion I have is to fix the new persons free starter decks. I haven't been able to get any sense the blue and white ( first on after the mono colors ) which I've logged on nearly everyday. Still says you will have a new one tomorrow, which hasn't happened in about 2 weeks.