The cosmic microwave background (CMB) has played a central role in developing the Big Bang model of cosmology. ACBAR's first data release provided the most precise measurement of fine-scale CMB temperature anisotropies to date. These small-scale measurements complement large-scale experiments such as WMAP and Boomerang. Since then, we have reanalyzed the data set using a more efficient algorithm and have included 30% more data. For the 2005 season, we rebuilt ACBAR's focal plane and doubled the number of 150-GHz detectors. Our new observations in 2004 & 2005 have tripled the volume of data, and will result in significant improvements to ACBAR's calibration and statistical error bars. After a brief review of CMB science, I will describe the instrument and the new algorithm, and then discuss the results we expect from ACBAR.