Here is the context:
SAN FRANCISCO (MarketWatch) Intel Corp. Chief Executive Paul Otellini is probably sick and tired of hearing about the looming death of the personal computer, and investors's concerns about his company's absence in tablets and smartphones.
So he came out of the gate swinging on the chip giant's conference call Tuesday, dropping the news that an Intel chip will appear in a smartphone in the next 12 months. He also mentioned that Intel has received the source code from Google Inc. for its Android/Honeycomb operating system, and is making sure its chips will power Honeycomb-based tablets, as well as tablets running MeeGo and Microsoft Corp.�s �Windows platform.
Thanks!
It's a mixed metaphor.
One "comes out of the gate" doing something means that they do the something from the very start. The metaphor is to horse racing. Before the race starts, the horse are contained in the "gate." When the gate opens, the race has begun.
On the other hand, "to come out swinging" is a boxing metaphor with a similar meaning. One comes out swinging, meaning at the very beginning they are on the attack.
Together, the imagery is a little confused.
In the text you cite, it means that the Intel CEO did not wait for questions or to reveal other news. He came right out at the beginning of this conference call with the "big news."
Many thanks!