no. it's too confusing for the lowest common denominator. even with the emerging support, it would probably still require a significant amount of knowledge on how to use and store them.

Lets look at some numbers. 
Bitcoin total valuation a few billion.  BTC = 350 each
Total Global Black Market a few trillion 1000 times more BTC = 350,000 each
Total Gold valuation 10 trillion 2500 times more  BTC = 875,000 each
Total NYSE market cap 16 trillion 4000 times more  BTC = 1.4 million each
Total NASDAQ cap 6 trillion 1500 times more BTC = 525,000 each
Total Fed Bond Market 40 trillion 10000 times more BTC = 8,750,000 each
Total Global Bond & Stock Market 250 trillion 62,500 times more BTC = 21,875,000 each
So mainstream = NO.  The good news if it gets to 1% mainstream ...   

I think they are, and I think it's a little bit dangerous still. At this point in time you still need to really know what you're doing if you plan on handling a decent amount of btc money.

Nobody knows bitcoin yet so its far FAR away from mainstream.

Here are some things to think about:
We recently hit a new ATH (over $350)
Bitcoin is all over the news
There is a lot more Bitcoin adoption happening

It is possible that Bitcoin is becoming more well-known by regular people.

Yes and No give it a few years 

No it will never happen, its unrealiable, price isn't stable, confirmations takes 2 long, no "real" value + there has to be few 1000s more bitcoins out there to cover the market needs..

At least in the USA, thank you to BitPay, it seems that Bitcoin is at the front door of the mainstream talking to the household people.

Question would be that household people at the doorstep would let the Bitpay into the living room to discuss further business or have a cup of tea/coffee

If they can pass the front door, Bitcoin will be in the main stream!!!  YAY!!!

Right now, many people in the US who got wind of Bitcoin invested lots of $$$ into the pre-order mining machines and others are spending crazy amount of money on Ebay not realizing they are buying expensive space heaters.  (in the next few weeks, when the news hits the newsoutlet regarding how large the financial loss related to the mining machines, it could hurt/scare the people at the front door...

People may slam the door on Bitcoin all of a sudden, or they may politely take the info, end the conversation, then close the door on Bitcoin

that could be an extra hurdle for the Bitcoin's success

I think it is, because Bitcoin make the same daily transaction as PayPal already.

No, PayPal is mainstream. Bitcoin is still just talk for most people, still will be a while until it's mainstream. Not to mention, at 400 dollars I would be a bit disappointed if it were already mainstream.