Nice list of review marks and links --
http://www.gonegold.com/gguide/homm4.shtml
A comprehensive Fan site --
http://www.strategyplanet.com/homm/preserve.shtml
almost Too comprehensive fan-boy site . . .
http://www.mmportals.com/heroes4.html
I don't have it yet, ebworld has shipped mine, should be here on monday or tuesday (hopefully). Looks great, as for leveling up, i think you have 3 choices instead of two, and that what choices pops up is dependant on your class / starting class / advanced class in some way. (for instance, an archer will get more combat "feats" than a cleric, right? but there is the percentage chance that the cleric will get "tactics" or whatever)
the music is a mix of heroes 3 and heroes 2, from what i've read. the multiplayer is limited, but hopefully that'll change with a patch (and hopefully a grid will be in the patch too, making combat a bit easier for those of us who always used that grid thing, like me).
all the heroes of the same class start off the same (so no more guys which start off with "logistics" as their speciality (giving them a +5% bonus to logistics each level), or people who grant you +1 resource / turn), but through the advanced classes you gain things. (an archer who learns scouting becomes a ranger, and as a ranger, gets a +5 to their ranged attack)
seems like a whole lot of fun, too bad i don't have mine yet! (well, at least i have my ex pack for The Sims to tide me over . . . how sissy is that? lol)