Woah. All this stuff is very impressive. Extremely impressive, in fact. 1) Tighter security to prevent the hacker issues 2) 2 dozen weapons 3) More variety of enemies + boss battles 4) Destructible body armor (Impressive for a graphics engine on the Wii to handle this. 5) Sprinting 6) Movable environment for cover 7) More open level designs 8) Deeper story telling 9) Online/Offline Co-Op 10) More online customization 11) Offline split-screen multiplayer (Finally, a game gets it right by allowing us to play against friends because we all know that trash-talking our friends is one of the simple pleasures in life xD) 12) More polished graphics.
I must say, if HVS can actually pull all of this stuff off in the final build, they might just redefine the Wii and the "limits" that many devs have used to excuse their laziness.
Even a fool is thought wise if he keeps silent and discerning if he holds his tongue - Proverbs 17:28 For all intents and purposes, just know me as The Mute...
What will be interesting to see is whether fans that dismissed TCon will give Con2 a chance. Reading through the IGN comments, I think so. To a certain extent, at least, HVS has to compete any modern FPS, not just those on the Wii to get that second look from people.
IMO, local multiplayer and coop are significant features to get gamers' attention, but I think the whole set of features is good, too. The 360 has a number of successful FPS that have these features (or fewer). If the story looks good, there are some good, distinctive weapons, I think this will get second looks--at least from those that aren't HD fanboys.