Fascinating - it will come down to 3 key states: Wisconsin, Michigan, and Pennsylvania. Whoever wins 2 of those 3 will be president. Wisconsin looks like it will go to Biden by a hair, Michigan still has many votes to count, with nearly all of them coming from heavily Democrat-friendly urban areas around Detroit, and Pennsylvania still has more than a million mail-in votes to count (again, many from urban areas), which also bodes well for Democrats.
All in all, it's looking cautiously optimistic for a razor-thin Biden win. His path to victory is slightly more favorable than Trump's, but I do mean slight. Trump being the belligerent bellend that he is however will naturally challenge the results through legal means if he winds up losing. He already held a stunning speech at 2:30 AM last night in which he not only claimed victory prematurely, but also called the results a massive "fraud" and "embarrassment for America"...
EDIT: Biden just pulled ahead in Michigan, and there are still 11% of the polls outstanding in the state, most in the Detroit area. It's looking a bit more positive now.
EDIT: Apparently even Georgia is still in play as many outstanding votes in the heavily urban Atlanta area are yet to be counted. If Trump loses Georgia it's over.