Obama was warned to not take executive order on immigration deportation, as it could cause a constitutional crisis. Obama said in his press conference that before the end of the year, he will act with an executive order if nothing happens in congress.
So, congress has until the end of the year maybe to pass immigration reform and avoid an executive order. If they do not do such, then expect around Christmas time for Obama to sign the executive order, giving immigration reform advocates a present for Christmas.
The next move is then the Republican Party's move to see if after he signs the executive order that they will actually pass immigration reform that the President likes better then his executive order.
Or they can ignore immigration reform and complain about how it is lawless, meaning an impeachable offense. If they allow his executive order to stand and do nothing but hold hearings and talk, then it will turn off their voters cause they will say "You control the house and the Senate, you can move to impeach him, so why don't you?"
So, they either move to impeach him or say they might have misspoken, either of which is good for the country. If they admit to misspeaking, then they can be shown as "liars" on everything they say.
If they continue down the impeachment path, it will activate more voters to remove the GOP from congress by 2016. It will also force other republican politicians to take a stand on the actions of congress giving ammunition to use against them in 2018, turning lots of those red states to blue states, and preparing for the 2020 census and the redrawing of congressional districts after the 2020 census.
A new majority, so GOP, please proceed.