While Microsoft says that it would still like to work with other phone makers, including Samsung and HTC, the move will likely push other smartphone makers who were making Windows Phones out of the market.
"Whatever flagging support Windows Phone had from Samsung and HTC will now either be further jeopardized or cut off," Ross Rubin, principal analyst for Rectile Research, told ABC News.
"As Nokia was willing to exclusively work with Microsoft, the two became such close partners that acquisition enabled less friction. Nokia was already, for all intents and purposes, Microsoft's handset vendor."
The Nokia acquisition is expected to close in the first quarter in 2014.