but it can't be sustainable until TWO very serious problems are fixed: Mining concentration and scaling. Of the two, scaling is actually the easy one.
Who cares? We shall see new high above $1200 by the end of the year.
That's like trying to predict the weather a month from now. It's unknowable because things have to happen that can't be predicted.
You may be right IF
We don't have a fullblockalypse. (probable without at least a SW upgrade)
The ChiComs don't launch a 51% attack (unlikely but possible)
a terrorist attack hasn't been found to be funded with Bitcoin
No more MtGox type exchange implosions
MtGox Bankruptcy (200K!) coins aren't sold to satisfy creditors
We don't have a wave of hacker extortions that trigger a widescale crackdown
Satoshi doesn't move his coins
An Altcoin doesn't overcome Bitcoins first mover advantage
Bitcoin doesn't fork contentiously making two chains that both somehow survive (extremely unlikely)
An unknown vulnerability of the code isn't found and exploited
some completely out of the blue Black Swan doesn't take us out in some way nobody has even thought of yet.