MSG.com has these renderings of what the new MSG will look like..
MSG.com adds that the lower bowl is expected to be ready for the 2011-2012 seasons and upper bowl for the 2012-2013 seasons.
Renovation will be done in phases with the majority done in the summer months to minimize disruptions. Building will remain operational throughout the NHL and NBA seasons
For more renderings click here.
Back in 2008 Garden officials said the renovations were going to be completed by 2010.
...a couple of years late but it looks awesome.