Wii comparisons: At week 44, Wii is where GCN was at 172.5 weeks (December 29, 2004), where GBA was at 38.0 weeks (December 9, 2001), where DS was at 50.6 weeks (November 17, 2005), where PS2 was at 55.5 weeks (March 21, 2001), and where PSP was at 82.3 weeks (July 4, 2006).
PS3 comparisons: At week 47, PS3 is where PS2 was at 5.3 weeks (April 4, 2000), where PSP was at 18.1 weeks (April 10, 2005), where GCN was at 21.9 weeks (February 9, 2002), and where Wii was at 6.6 weeks (January 11, 2007).
DS vs PSP: Weekly shares of 41.5 / 58.5 bring the total shares to 75.3 / 24.7, back where things were early December 2006. At this week's rates PSP catches up to DS in 438.4 weeks (February 25, 2016). If DS stopped selling, PSP would catch up in 127.4 weeks (March 11, 2010).
PS3 vs Wii: Weekly shares of 35.2 / 64.8, bringing the total shares to 24.4 / 75.6. If Wii stopped selling, PS3 would catch up in 186.5 weeks (April 28, 2011).
PSP vs Wii: At this week's rates, Wii doesn't catch up to PSP.
PS2 vs DS: At this week's rates DS and PS2 meet in 20.9 weeks (February 23, 2008) at ~21.0 million apiece.