Well the big quesion of the game is the 3 parts its broken into, I know at the last blizzcon the did a audience vote, and attendees went for this option.
The problem is -
1. Buy copy now and get
a. Approx 50 bucks cost
b. Online play - all races and content for online play ranking
c. 1 race offline play mode campaign
2. The other expansion part 2
a. Approx another 50 bucks
b. Same as before - online play no changes
c. part 2 of offline campaign
3. the 3rd expansion
a. approx another 50 bucks
b. same as before - online play no changes
c. part 3 offline campaign
Summary -
cost $150.00 total approx
get online play
and pay 50 bucks for each offline campaign
so 150 dollars for a game just to play offline campaign, when the 1st 50 gets you the online, save 100 bucks for offline content. This strategy is up for grabs success wise, most wont bother except few hard core fans willing to spend additional 100 bucks just for some offline content since no lan option is given. Sounds ok but the problem with this strategy is the game type, its a RTS, as traditional most RTS is about combat challenge of person or teams, not like RPG which offline content is more desired as its single player oriented. Offline content RTS is generally limited market and not played long term. Most dont play RTS single play campaigns for extended time frame, its about challenge combat with others that RTS types fall in favor to. So this extra expense for small offline content few the sales will be very poor for the other 2 parts, if the original content is fee based to add them in, which since its blizz / activision, activision typically nickle and dimes every penny from a player they can, so we are given a RTS game thats going to fail past the 1st part hype release. Least for now, unless they change its over all strategy of content style for offline based users.