News reports say migrants are flooding into Europe, with claims of possible 1 million.

What are the likely impacts of this on Europe?

Will it change Europe forever, Socially and economically?

Banjo,
Probably not and I don't think too many "refugees" are going to find their better life in Europe, as the Islamic state grows and takes control of north Africa, the middle east and west Asia a lot of them will return because conditions will be better for them there than in Europe.
I obviously read a lot of nationalistic material and communicate with nationalists all over the world via social media and they're not overly worried about longer term impacts simply because the ordinary Europeans who've never cared about politics are already rising against pro-immigration parties and NGO's.
It's been quite amazing to see the change in the type of material my French, German, Austrian and Italian Facebook friends are posting, these are not Nationalists but people I've friended based on a common interest in music.
From pictures of musicians, cars, and the day to day trending photos and such they've moved on to sharing the posts from the GDD page, PEGIDA,Golden Dawn, Sweden Democrats, Jobbik Liberty GB and the like.
Now these are really normal people, a lot of them I'd even consider to be left leaning in other areas such as Gay rights and such, they all seem to work, have families and mortgages, these aren't skinheads or hooligans.
In fact the old "Far Right" campaigners are largely staying out of it as Varg Vikernes explains:
http://www.youtube.com/watch?v=WwTM2B6MUJU&feature=share
In fact many Australian Nationalists have also agreed not to take up prominent roles in UPF and Reclaim Australia rallies for that reason, the ordinary people are now saying the things we used to say, so we need to move on to other things and leave them to it.

Dr Christine Langenfelds of the German Foundation For Migration and Integration claims that to date there has been no empirical study of the qualifications and education of refugees. There are currently seven reception centres in Germany where migrants are interviewed for job readiness and skill levels and since July they've assessed only 270 out of a potential 250,000 cases. Further to that even in "developed" Syria and Iraq only about 6% of the people have higher education qualifications and German analysts guess that perhaps 10% of the expected 800,000 migrants arriving this year will be employable.
Germans are also worried that because the migrants will not be productive even if employable in menial jobs that there will be calls from employer groups to lower the minimum wage and Merkel being Merkel will give in to them.
http://www.facebook.com/GDDVerbund/posts/626696244139813

//Will it change Europe forever, Socially and economically?//

It seems unlikely. In 2013 there were 742 million people in Europe, so I can't see an extra 1 million making much difference. They've probably increased in population by more than 1 million since 2013 anyway and it doesn't seem to have done them any harm.

Toni, no it won't but it's wrong to say that there will be no negative consequences, the effect of third world immigration is overwhelmingly negative, it's simply been mitigated to a large degree by dispersal of immigrants over a wider area and by media and government cover ups and white washing of the facts. The fact that the rapes, financial fraud, drug dealing, gang violence and other crimes endemic in migrant groups have been spread over time and geography makes it easy to describe them as isolated incidents but they're actually very common among immigrant groups. Overall migrants to Germany commit crimes at four times the rate that native Germans do and Muslims, Lebanese, Turks, Somalis, Koosovars and Albanians in particular are notorious.
Example.
Apologists for immigrants can sidestep context and say "Oh well this attack by Lebanese happened in Dallas, this one happened in Dandenong, this one happened in Footscray all over a period of a year, they're not connected and there's no real problem".
Yet they are connected, there is a pattern and there is a problem with Lebanese violence, the Lebanese ancestry is the context and the thread that joins all the attacks.

The immigration into Denmark, Holland, Belgium and France has been
disastrous. Just yesterday there was a video doing the rounds of two
moslem men slapping, punching and kicking a teenage girl because she
was dressed immodestly wearing jeans and a top with short sleeves.

You see moslems have a fixation about women's legs, arms and hair.
When they see them they can become uncontrollable.
At least that is the excuse they give the judges when caught.