The Pantone Goe System adds 2,058 additional colors. Often time with legacy Pantone colors, a match color may fall between hue increments. Also the numbering got awkward when what was originally a three-digit library received new colors squeezed in by providing a forth digit. It's a system that was in need of an overhaul. Goe has much smoother color transitions from chip to chip and consistent numbering. But since existing corporate branding relies on legacy Pantone colors, Goe has to append rather than replace. It will be a while before the industry embraces the new standard.
On the hardware front, Pantone certified inkjet or laser printers include firmware to override CMYK values (actually using L*a*b) to reproduce Pantone colors on specified stock. The costly licensing and calibration is not generally updated for machines in the field (already sold). Therefore only the newest printers or RIP software is able to support Goe. Printers available this year will include Pantone Goe certification. The HP Z3200 is one example. Of course, Goe is still a "go" with offset printing.
As far as Pantone books are concerned. If you do much offset printing, it can be useful but you'll still need the legacy library. You can also look into the
Pantone Color Cue 2, which includes multiple Pantone libraries, including legacy, pastel, and Goe.