Assad has been deposed and may be dead.
His troops were overrun originally by various "rebel" factions, many of them being radical Islamists (not exactly "nice guys") and there were many reports through the day that his forces knew it was inevitable they'd lose and rather than die they abandoned both their uniforms and positions.
Then, in a rather dramatic (but so-far as I know unconfirmed) report from public flight radar data an airplane that appeared might have had Assad and his family on board left, was ascending and then looks like it may have been shot at, hit and entered an extremely rapid descent and appears to have crashed. However, later it was reported that Assad and his family had reached Moscow and were given asylum -- so either that wasn't his aircraft or had a very good pilot (and more than a bit of luck, I suspect.)
Syria is a tough nut. Assad was clearly not a nice guy, but he lived in a world full of very not-nice people. There are opinions all over the board as to whether he was the keeper of peace (albeit via rather extreme means on more than one occasion) or a brutal dictator who had no compunction about gassing his own to remain in power. One of the problems of war is that the truth is usually the first casualty, and Assad had been in power for decades, faced many attempts to depose him and they weren't doing so with harsh language. Thus the challenge in any attempt to figure out what's what.
Don't take lightly the geography. Syria is in a very interesting place; Turkey to the north, Iraq to the east, Jordan south and Lebanon west sort of along with a little piece of Israel. The geopolitical aspects of this are obvious which is why Syria has been a flashpoint for a good long time, never mind the nation's direct sea access.
Netanyahu has made a public address taking credit for Assad's fall, stating that his nation's attacks on both Iran and Hezbollah were proximate causes. Perhaps true but there's a caution here in that Syria was a fairly-significant balancing force against extraordinarily violent people and Assad wasn't voted out of office, he was basically shot out of office.
Will those who did so consider the issue resolved and lay down arms, leading to an outbreak of peace? I'll take the under on that wager given the general nature of that part of the world over the last 100 years or so, never mind historical context going back way further than that.
This could quite-easily be the start of something much worse than what we've seen over the last 20 or so years in the Middle East. Both nature and politics abhor a vacuum and here we have one with pretty-much everyone in the vicinity being more than willing to pick up a rifle, RPG or worse at the drop of a hat.
This much I can say with certainty: We have no good reason to get involved in this in any way, and the further away from it we stay the better from an American point of view. Let these folks figure out on their own whether they're tired of war or not.