What are the advantages of the Stonewall attack? I stumbled upon the Stonewall attack, and it looks pretty strong, and I especially like the fact that it is strong against computer programs.

I would like feedback on this attack, and if this is a move I should consider as a beginner in chess to improve my play?
From the Wikipedia article that you linked to:


  The downsides to the Stonewall are the hole on e4, and the fact that the dark squared bishop on c1 is completely blocked by its own pawns. If Black defends correctly against White's attack, these strategic deficiencies can become quite serious. Because of this, the Stonewall Attack is almost never seen in master-level chess any more, although it is seen occasionally among club players. 


The problem is that although the fortress may be solid (at least to begin with), White's attacking options are limited by the bad bishop. In addition, by setting up the fortress the initiative is handed to black, who has various options to break down the fortress (generally a good opening for white would keep the initiative). The article suggests:


  Black has several ways to meet the Stonewall. One choice which must be made is whether to fianchetto one or both bishops; Black can meet the Stonewall with a ...b6 and ...Ba6 aiming to trade off the dangerous white bishop on d3, and a kingside fianchetto with ...g7-g6 takes away White's idea of attacking h7. An early development of Black's light-squared Bishop to f5 also cuts across White's plans.


Other obvious attacking options for black are to hit the base of the chain with b5 and b4, or to castle queenside and attack on the king side with g5. Setting up a fortress like this often seems strong, but in fact the opposite may be true, and in fact is simply providing "hooks" for the opponent to mount an attack. As also stated in the article


  Black playing the Stonewall Variation of the Dutch Defense is seen occasionally at master level.


and one could also surmise that such defensive formations are, in general, more appealing from black's perspective.