Monday Mutant 78: Streampunk

Shade in some cells black such that the black cells are all connected to each other through their edges, and no 2x2 cell area within the grid contains all black cells. Numbers in a cell indicate the sizes of the orthogonally contiguous groups formed by black cells sharing a corner or an edge with that cell. For example, "3" means that the cell shares a corner or an edge with three black cells, and they form a single group, whereas "1 2" means the cell shares a corner with three black cells which form a group of two cells and a single separate cell. Cells with numbers cannot be black.

Before you complain about me featuring a "classic" puzzle type (a modern classic, mind you, but a classic nonetheless), I quote a post of yore: Monday Mutants is a series in which I will attempt to experiment with "mutant" puzzles. These could be existing puzzle types with an unusual change in the rules, hybrids combining elements from multiple puzzle types, or puzzle types neither invented nor popularized by Nikoli. Also remember that in the weeks after that post, I played around with several variants on said "classic" puzzle.
Two of my Cross the Streams puzzles have been published in Akil Oyunlari! I encourage you to get a copy of the magazine so you can see them. Don't let the Turkish language daunt you; the magazine's LiveJournal is devoted to making the puzzles as navigable as possible for English speakers. :)