Absurd.
You don't understand how Bitcoin works and where it needs help.
LTC and doge will both be added to BitPay et al and will both surge to billion dollar valuations. LTC and doge cover different niche markets so one will not replace the other. They both compliment Bitcoin and will assist Bitcoin otherwise Bitcoin will not be able to go to the mainstream mass market next year which is the plan.
Im sorry i was so superficial in my earlier post. Let me elaborate a bit.
Coins will come and go in the future too. Litecoin will not die. It will survive the low period and perhaps gain some value in couple of years. I was more optimistic about Litecoin in few months ago, but now i am not that sure if it will hit a 25 USD again in a year or two. What is this litecoin niche? Could you explain where is it unique or why should it hit 25 or 50 USD again?
DOGE will not replace anything, but i suspect it will be more successful than the Litecoin, simply because of its character.
The current top coins have plenty of room to grow. One should not replace another. Cryptocoins market is still extremely small.
I am not going in to detail on this, because this is not the right topic but BTC can become a more of the safe haven payment instrument in few years time. People need time to learn what crypto-currencies are about and trust issues will ease in time. Liquidity will increase and solid coins will gain value against FIAT.