WarHawk supports your XMB friends list, so there's no need to create a separate list of friends like in Resistance. The game also contains clan support which acts as a separate list for your clan, alongside other clan specific features such as a clan leader and clan emblem.
Games can be played on peer-to-peer or dedicated servers. Sony and Incognito will be providing a number of dedicated servers that will constantly host public matches. You can also turn your PS3 into a dedicated server so you can host matches without having to play the game yourself.
Deathmatch - every player for him or herself, the player with the most points at the end wins the round.
Team Deathmatch - similar to deathmatch, except players are split into two teams, with the winning team determined by the aggregate number of points.
Capture the Flag - steal the other team's flag and bring it back to your base to get points. Most points wins.
Zone Mode - the map is split into bases that can be captured. Staying in the base increases the base zone allowing for more weapons to spawn and points scored. If two zones meet that are owned by the same team they are merged into one to gain even more bonuses. The team with the most points wins.
Both Team Deathmatch, and Capture the Flag feature a base system that allows for more spawn points and vehicles to be created. However, these bases don't have a growing influence like in Zone Mode.
Retail and PSN versions
WarHawk is available in two different forms: a downloadable version for $39.99, and a retail box that comes on a Blu-Ray disc for $59.99. There are no differences with the game itself, but some extra functionality features come with the retail version. The retail version is bundled with a Jabra bluetooth headset for voice communication. Furthermore, the Blu-Ray disc can be used in "game sharing mode" meaning that one disc can be put in multiple PS3s, so that only one copy of the game is needed for local area network play.
A special note about the PSN Version: WarHawk is the first downloadable content that is directly tied to your user account. Sony explains the restriction thusly - "One time fee for download or use solely by the purchasing PSN account on up to five PS3 units, with no more than one activated PS3 unit within a 24 hour period. Content may not be used by any other account." This means that family members who wish to play the game on the same PS3 must use the same account.