This may depend on how the question of the 1 MB max blocksize limit is handled. One thing is certain without an increase in this limit, and a hark fork is necessary for this, Bitcoin will be dethroned by a competitor. Once the limit is reached transaction fees will skyrocket as an ever growing number of transactions compete for the 1 MB space every 10 min. Fortunately Gavin Andresen understands the need for this. So do other Bitcoin developers. The real question in my mind is will they muster the necessary community consensus to make this hard fork happen?
I don't think there's any plausible scenario in which the death of Bitcoin is somehow an opportunity for some altcoin to take its place. The death of Bitcoin would be the death of cryptocurrency.
I don't agree. BTC is currently caught in the middle of two somewhat conflicting pulls: 1) a means of commerce and 2) and a deeper evolution of modern politics: that is, the changing balance of power between the individual and the state. At this point there are alts mpving full speed ahead in both these two directions, while btc seems paralyzed in the middle. In first direction, alts like Via are moving forward with sidechain possibilities and faster transactions. In the other direction, anons like Cloak and BTCD are moving rapidly towards privacy evolutions that BTC has now forsaken.
Evolution, sythesis, antithesis - this is the nature of life. BTC and crypto in general does not stand apart from this flow.