The nature of Bitcoin is that it's quantity is limited, until 2140, there is the production of new bitcoins to reward mining which is the voluntary provision of computer resources to support Bitcoin, by 2140 the reward mechanism is expected to shift to fees on transactions. With the cap in 2140, the nature of Bitcoin is deflationary.
Although many would talk about it's acceptance or lack of acceptance by financial institutions, that is immaterial to the survival of Bitcoin, it is after all a peer to peer solution to digital cash. What endangers Bitcoin is if bitmining is no longer of interest to independent miners. This can arise by several sources, if the preprogrammed geometric decline in inflationary rewards is not offset by fee based rewards to offset the capital investment in equipment and if the ongoing arms race in equipment required increases costs and lengthens the payback as the reward lottery benefits those with the most capacity hence newer more capable equipment depresses the profitability of older equipment. So long as the bitmining services remain popular with independent miners, the system can not be subverted. If the peer to peer nature remains the Bitcoin would still be available and trusted and in the long term should increase in value. Unless bitmining drops in popularity, the currency is not in an unrecoverable plummet as few other mechanisms could remove it.
However, it is an emerging currency and isn't widely used or recognized so it's very volatile and will likely remain volatile for some time. It is certainly not in a steadying trend. All that can be said is it will likely be all over the map for quite some time to come.
Is now the time to buy? That really can't be answered.
I am disappointed that the Bitcoin Wallet applications do not make the built in escrow service readily available. I suspect that they are thinking of that feature being something they could charge for or that third party escrow is a service they do not want displaced.
A more appropriate measure of the availability and strength of the protocol is the two week security recalculation to keep the transaction commits to about 10 minutes. So long as the cryptographic challenge is increasing, bitmining is popular and security is increasing exponentially.