Not sure what it is like for IFR, but I had a chat to the CASA guys at the Wide Bay Airshow a couple of weeks ago regarding it's use in VFR ops; and this is what they said:
We deem it sufficient to have all your weather and NOTAM's stored on there (no paper copies needed). They have no issue using it for charts and navigation, DAPS etc as long as you have redundancies in the aircraft (ie. printed the paper copies of the ERSA entries etc before you leave. Which can be done from the iPad). Also you must not be solely relying on it as a navigation source.
Off the record the bloke (an ex-CFI) said that he personally sees them as far safer and more efficient in light aircraft. Especially single-pilot operations; for the reason you stated... no fumbling through bags etc. He also said that at night they are wonderful as they are backlit, eliminating they use of a blinding torch trying to read a chart.
He said that CASA is working on officially clarifying the issue currently.
Hope this helps.
Rob.