Has any other DLC been announced, i thought there were 2 more that were supposed to come out after HH..

June for old world blues, July for lonesome road.

I dont know of any date's for release.

This. At the moment thats what we know. Nobody knows if there will be more other than those two.

Unless/until we hear otherwise, through official channels, it is best to assume that the remaining two will be all there is.

Well, I'll tell you what's next. I made some predictions a while back when Dead Money was released about the direction the DLCs were taking based on dev comments and hints in Dead Money.
Most of them have come true.

Honest Hearts I predicted would show us the burned man and New Canaan. Instead we got Zion and new Canaan was destroyed, but we did see the Burned Man.

Old World Blues I predicted would bring us to the big empty. It has been proven correct. In old world blues we will be brought, possibly kidnapped, to the Big Mountain (Big MT, big emptee, big empty, see?) facility which is a pre-war research base that has tons of old tech and many dark secrets. You can expect to see psychological and medical experiments gone awry, to tangle with lobotomized humans who have been surgically modified to be compliant servants, and to struggle against some person or entity that is doing horrific experiments at the facility, as were done to Christine from dead money.

Lonesome road will take you down the titular lonesome road to the "divide", which is said to be a one way trip. But don't believe it. The courier will be the first to come back if anyone will be. Here you will face the dangers of the road and the divide, which have killed whole platoons of NCR soldiers and Legionaries. I don't know what is in there exactly, but I've heard of "storms from the divide" which are capable of flaying the skin off your body from Johnson Nash when talking about the "second courier" who turned down the chip job. Speaking of him, he's likely to be Ulysses, a patriotic guy with dreads who is or was somehow working for Caesar and has some sort of history with you. He also helped Christine to escape the Big Empty, so there's that as well.

It's assumed we'll meet Ulysses at the end of the Road.