I seriously doubt that when one company buys another similar sized company they throw half the business out of the window. They could sell the microcontroller and or memory business though so you guys (not me for sure!) could end up with MAtmelchip.
You may be right that it doesn't seem to make sense, but it happens all the time. There is a school of thought that a company doesn't have a portfolio of products, instead, what it has is a portfolio of customers.
If the wanted 1/2 (of the business) can operate without added fix cost (to the acquirer's original fix cost), and can operate with small enough variable cost - the numbers can indeed work out. Basically, the acquirer added a few product line for their existing customer, and acquired a whole bunch of new customers, and (figuratively speaking) just need the existing sales folks (core+new-x) to carry a few more brochures and make a few more stops.
Of course, ideally, x=new so the end result is just the existing sales folks (core) would do. Actually, the sales folks are the ones they most likely keep - since the existing relationships needs to be kept at least for a while. It is the x in the lab, in the production floor, in the accounting office... in those categories, the ideal value of x is the number of acquired employees in that area so (core+new-x)=core.
The other 1/2 of the business they will try to convert, or they can be re-sold if profitable to do so. If they start to make a line of business more independent, that is a good indicator that line of business may be sold.
That brings us to Dave's point which I agree.
If dialog buys Atmel, we can kiss goodbye to the small customers. Including the Arduino folks. They are quite important for a number of reasons.
But not important financially (to an MBA mind at least)
So, the key of the future would be "What is it that the MBA's (particularly younger) see?"
* I amended it with "younger ones". Younger ones are less exposed to real-world experience thus more driven by raw numbers on a spreadsheet.
I suspect even within Amtel and years before this acquisition was dreamed, the "Arduino folks" category was long ago dropped off into "residual value" area of the spreadsheet. Residual value (or whatever Amtel's company lingo calls it) is when no real new development investment is made, but just production related investment for as long as the product line(s) are profitable. Most likely, this "Arduino folks" products is also the group under the most sever price pressure so there is not a lot of money to be made.
I suppose none of us not sitting at the table has the real answer now, but we will all know 3-6 month after the acquisition and then we can scream, or not.