I have installed in Window 7 environment Anaconda 2.0. The default Python is 2.7 but also Python 3.4 is installed. I am able to activate Python 3.4 with the command "activate py3k". After this Spyder IDE does work right with Python 3.4 But 1) I'm not able to start Ipython Notebook and QT Console with Python 3.4 2) I'm not able to start Anaconda with Python 3.4 as default (so that also launcher starts the three apps -Spyder, Ipython Notebook and Ipython QT Console with python 3.4)
As asmeurer said, when in your py3k environment in the command prompt, you can launch a 3.4 kernel with the ipython notebook
command. You can run both a 2.7 and a 3.4 at the same time if you specify a different port, for instance, ipython notebook --port 8080
The 2.7 will default to 8888.
Note that, by default, IPython will look in your current directory for notebooks and store them there if you create them, so it can be helpful to create a directory just for Python 3 notebooks and either cd to it before launching or specify a directory with ipython notebook --port 8080 --notebook-dir C:\\Users\\[User name]\\Documents\\ipython3notebooks