Complex sentence: In December 2011 a second tower of the Sheraton will open with over 2,000 more rooms to make the Sheraton have 4,067 rooms and suites.
Split into simpler sentences: In December 2011, a second tower of the Sheraton hotel will open with over 2,000 more rooms. In total, the Sheraton hotel will have 4,067 rooms and suites.