If Bitcoin is destined for high finance (and litecoin destined for major purchases like cars, fridges and computers), odds are that one or more of the other crytocurrencies will prevail for routine expenditure (groceries, coffee, fuel).
I predict Dogecoin has the potential to become much more than the leading tipping currency. I do not know this as a matter of fact of course, but I reasonably believe it entirely possible that Dogecoin is a major contender within the next 3-5 years for the following reasons:
1. Highly developed community
2. Huge investment potential (you can buy half a million doge for about $150 dollars at the moment)
3. Superb architecture
4. Straightforward wallet security in terms of encryption and wallet locking
5. Massive reputation as a major cryptocurrency
Of course there are other contenders. And of course, there are people with vested interests in other currencies who may react angrily (I admit I hold interests in Dogecoin which may well have affected my objectivity).
But this is my very feeling. Much responses.