Uberena is a micro arena map based on a SC1 map by the same name.
It's similar to Team Micro Area and Nexus Destroyers -- two teams of up to four players try to out-micro each other, accumulating killscore and gaining more units in order to ultimately destroy the opposing team's base.
There are several significant improvements:
- Larger and more diverse terrain
- Superior unit selection interface
- Per-unit killscore/cost balance
- Better hero options
- Additional user settings and game modes
Most of the available units are straight from melee and have default stats, except for cost, which is mineral-only and adjusted to reflect the unit's usefulness in direct combat. The amount of minerals players can spend increases as the game progresses. This allows players to easily become familiar with many different unit interactions on many different scales, which is knowledge that can be directly applied to actual melee matches.
Main thread: http://us.battle.net/sc2/en/forum/topic/628259087
TL thread: http://www.teamliquid.net/forum/viewmessage.php?topic_id=219892
Map image: http://i54.tinypic.com/2mct010.jpg