When the meme dies, the coin dies IMO. That's what I'm watching for, when people get sick of the meme.
When (or if) the meme dies, the devs/community will just make adjustments to the brand (name, logo etc) where required.
The amount of developments with Doge is astonishing though for a 2 month old coin......just today they launched the lite wallet (Bitcoin is the only other coin to have a lite wallet).
The number and speed of projects is directly related to the huge catchment of talent they are tapping into, and that will only grow.