I would like to second Pizza Luce for food and beer. They have a great tap list. Also, if you are looking for a good selection of craft beer or some homebrewing ingredients or supplies take a look at Last Chance Liquor. The Electric Fetus is great for new and used CDs and other hipster stuff.
I went to UMD...lot's of good memories..House of Donuts, Johnny Rays, rock climbing in Lester Park, Canal Park and Park Point. Lately I have been going to Duluth for July 4th..love the fireworks there. The Tall Ships this year was very cool too...I love Duluth.
If you like to get out and explore and find that the Northshore is too busy, head straight north out of Duluth towards Island Lake. There is a lot of public land for hiking, hunting or just getting away.
Within a few months my to-do list in Duluth...work out at the Duluth 'Y', which just went through a renovation & looks great! Sometimes I'll go to the SMDC Fitness Centre and then off to Bixby's Cafe (Woodland Ave & St Marie St)...I'm not much of a 'mall' person so I can't say a lot about the shopping scene here. I do know I'll be outside all the time this summer...best place I've found to take cityscape photos of Duluth, I discovered while hiking last fall - Observation Park at 10th Ave W & 3rd St...there's a baseball field, and behind that are some rocks, as you look around you get the best unobstructed view of downtown, the bridge & the hillside!
The railroad museum is really cool, you can get into the old train cars and engines and walk through them. I liked it alot and took a lot of pictures.
I want to take the train ride up the shore this summer when I'm there. I think it goes up to Two Harbors. I go through Duluth quite often.