A more accurate statement would be that after nearly four years, competitors have finally started to catch up to Canon.
Perhaps more accurate still is that the competitors, especially Sony and their sensors as partnered with Nikon, Pentax and Fuji, have significantly OUTPACED Canon's development in the last 5 yrs.
Canon's DSLRs have provided very good performance, especially at higher ISO since they implemented their CMOS sensor WAY back. However, since the intro of Nikon's D90 about 5 yrs ago, the competition has steadily improved low iso read performance (& hi iso to a perhaps lesser extent) to such a level that Canon now has an obvious handicap in the fixed pattern noise department.
Whether or not you find this an issue for your own work is not the point, it's just a fact. I'd like a replacement for my 7d that I can also press into high DR landscape use with fewer limitations.
I'm eager to see if Canon has pulled at least the ears of a rabbit out of a hat with the 70D.