The Haswell architecture offers up to nine hours of battery life, faster graphics, and so much more. In the graphics department, this chip is 90 percent faster than its predecessor. The fourth-gen guts have made the biggest upgrade in the battery department of any Intel chip ever.
It does this by pulling less power for CPU tasks, and has some sophisticated sleep modes that cut back on the power the rest of the machine is using. So, for example, you'll get more time for HD video streaming. So while it's not a difference you'll see in these new MacBook Pros, it's something you'll definitely notice in a big way.
Both the 13- and 15-inch MacBook Pros start shipping today for $1300 and $2000 respectively.