Hell no, this was the right move for them to make.
They made some pretty bad mistakes and they had to lower the price this far. You can't cut your prices more than once a year or so without customers getting nervous. Honestly a price cut to $199 wouldn't be enough. Imagine one more year of mediocre 3DS sales at $199 with the PS Vita being out.
Also at this price people who want a DS can basically get a 3DS for the same price. This was definitely the right move.
Now all they need to do is announce Super Mario Bros, Brain Training, a 3DS enhanced Pokemon Grey and make clear they are targeting the mass market again.
Nintendo lost loads of consumer trust over the last months. It's good to see they realized it and hopefully they'll learn for the WiiU launch.







