Based on the latest Media Create hardware numbers...
DS vs PSP: Weekly shares of 59.5 / 40.5 bring total shares to 68.3 / 31.7. If DS stopped selling and PSP continued at this week's rate, it would catch up in 329.9 weeks (September 6, 2015).

X360 vs PS3: Weekly shares of 21.5 / 78.5 bring total shares to 24.5 / 75.5. If PS3 stopped selling and X360 continued at this week's rate, it would catch up in 417.4 weeks (May 11, 2017).

PS3 vs Wii: Weekly shares of 43.1 / 56.9 cap PS3's string of Media Create weekly victories at 10. It's also the highest Wii number in over three months. This brings total shares to 28.2 / 71.8. If Wii stopped selling and PS3 continued at this week's rate, it would catch up in 261.8 weeks (May 17, 2014).

Week over week, Nintendo systems are slightly up, while everything else is slightly down.

Through the first nineteen weeks of the year, almost everything is down by some degree. Here's how the year-to-date year-over-year percents stand as of now.

Wii: -64.0%
DSL+DSi: -1.3%
PS2: -50.9%
PS3: +28.0%
PSP: -42.8%
X360: +246.2%

Home hardware: -36.3%
Portable hardware: -24.4%
Sum of all hardware: -29.2%