You guys see the tech tree?
http://well-of-souls.com/civ/civ5_technologies.html
Wow, that looks very condensed! Not sure if it's a good thing as in speedy game play or a bad thing as in speedy game play. Or maybe a smaller tree means you'll use each tech for longer periods while researching the next will take longer then usual.
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hmm I didn't know this but units can no longer be completely destroyed.
http://www.escapistmagazine.com/news/view/99021-Civilization-V-Offers-New-Strategic-Combat
"Another big change is the combat system. Units are no longer destroyed if they lose a battle, which means that civs can spend much more resources on maintaining their armies as opposed to cranking out new units. The combat that we saw took place completely outside of a city, and positioning and terrain are much more important. "In the past, combat revolved around stacks [of units], which our fans affectionately call 'stacks of doom,'" Shirk said. "We wanted to pull combat out of the cities, and make every unit important." No two units can occupy the same tile, even friendly ones, so positioning on the battlefield becomes very important. Ranged units, like archers, are used to soften up the front lines from up to two hexes away, but they are vulnerable to attacks from melee units. The result is an emphasis on battlefield tactics instead of most Civ games which favored the civ that was able to crank out the most units."