When the G6 was announced in 2004, I already had a G3 and, although tempted, decided not to upgrade to the G6. After a while, it seemed that the G6 was the end of the line for the G series but then the G7 was a surprise announcement in 2006. The G7 has been followed by a new G series every year from 2007 through 2010 when, once again, there was a two year gap and rumors of the G series coming to an end. Those rumors ended with the announcement of the G15 a few weeks ago.
(As a side note, the G4 and G8 model names were skipped in the past just as the G13 and G14 names have been skipped most recently. That is, there was no G4 or G8. Amusingly, the G4 and G8 are sometimes praised on Internet discussion forums for their quality and features. I expect the same praise to eventually be awarded to the G13 and G14.)
The G7 was a nice looking compact camera but did not have the articulated display screen featured in previous G series models. To my further disappointment, the G7 did not produce RAW image files. To many people, these shortcomings meant that the G7 was not a “real G”. All G models after the G7 have included RAW image capability but the articulated display screen did not return until the G11. I passed on the G7 but bought a G9, then a G12 and most recently a G1X.
My point (and yes, there is one) is that there was a two year gap between the G6 (which had an articulated display screen) and the G7 (which did not). There was also a two year gap between the G12 (which had an articulated display screen) and the new G15 (which does not). The G7 was viewed as a test of the compact camera enthusiast market. Is the G15 also a test of the market?
Fortunately, the G15 can produce RAW image files. In fact, the G15 seems to be more like a G12 that has been made more compact (by eliminating the articulated display) than it does an updated G7.
Will there be a G16? Who knows? My thinking is that Canon currently offers too many enthusiast compact cameras (G1X, G15, S110, EOS-M and an advanced EOS-M essentially announced). I expect that, depending on sales volume (of course), either the G1X or G15 will be dropped. But, as Canon has shown in the past, “dropping” a product may really mean a two year gap until the next model is announced.