As a relative newcomer to Bitcoin, having completed just a dozen or so transactions through a couple of exchanges plus a couple of actual purchases, I have to say I wish it success.
I've read through a couple of threads here about the biggest challenges to seriously widespread take-up that it faces and it has all helped consolidate my technical understanding. However, I do not recall seeing any discussion about what seems to me to be one of its biggest challenges/threats - in fact arguably THE biggest of all - namely being PERCEIVED as a serious threat to the existing currency regime by those whose wealth and power is defined by it.
Short of cataclysmic breakdown of the present Dollar-defined fiat system, the traded volumes of Bitcoin are likely to remain so minute by comparison, that it will always be a simple - almost trivial - undertaking for the Central Banking cartel (through their existing primary Broker/Dealer network) to engineer vast Bitcoin/Dollar (or whatever) volatility sufficient to forever cripple it as both a reasonably predictable store of value and reliable medium of goods exchange. If it really is seen as a threat, then that is probably exactly what will be done. IOW, so long as it remains on the margins, it may be tolerated; but if deemed a serious threat then, one way or another, it will be dealt with - or so it seems to me anyway.