So you can play as a marine...

Will players just drop the DH charachters and want to play as these super hard paragons of drstruction?

Is each release replacing the last? 

Erm... no?

Dark Heresy, Rogue Trader, and Deathwatch all have different themes, pros and cons. I love Dark Heresy and Rogue Trader, because they are about the humans that make up the Imperium. Deathwatch.... I'm willing to withhold judgement on until I read it, but I think it's safe to say that if you don't find combat interesting, you won't like Deathwatch.

Some will I'm sure.  Whenever a new RPG comes out a certain percentage of players is lost by every other RPG.  At least in terms of actual play time.  I'm sure people will keep buying DH books though.

I see Deathwatch as "ice cream."

Delicious and fun sometimes, but not as a main course.

So I can see Dark Heresy players taking a break to experience some uber-combat, but they will return.

Depends if they give us more than just a tabletop combat game by another name.

Must say I'm on the fence re the core concept, and I'm seeing contradictory information online about what the designers are trying to give us, on one DD Ross stresses Space Marines are more than just killing machines (even mentioning envoy type diplomatic missions etc), in the recent review linked on this board he stresses Space marines are just about combat and are monoskilled killing machines. I'm struggling to decide if the game will be for me.

I really doubt that. DH and DW are two different games, with two different approaches.

Here's an example:

In the Baron Hopes adventure the characters come to spend some time looking for information among the local serfs. There's an extra table for groups who have characters from the Ministorum or Mechanicus, this table explains that the serfs have never seen a real priest before and for them it's probably the only chance to be blessed by one (or confess etc.).  The table goes an extra step to show that the group can perform good deeds for people who have almost no hope for betterment in their lives. For the tech-priests it could be an even greater revelation because they truly are the one eyed men among the blind when it comes to technology. Suffice to say the serfs see the characters as humans.

Now imagine the same with a DW kill-team, the avenging angels of the emperor's wrath.

The hulking brutes who can arm-wrestle an ork and win.  The serfs would be terrified by them, because frankly for most humans the SM are beings of legend. Role playing space marines would not happen in interactions with the masses, but rather with people who wield power, like highly placed members of the IG or the commisariat, planetary administration etc. 

But that's only my opinion about it.

Perhaps, but not anyone I know. We've been playing DH for years and built up characters we care about and want to progress. I imagine the majority of players will feel the same way (provided they're enjoying their DH game).

For us, at least, this will just be yet another evening sacrificed to the Imperial cause. And, may I say, gladly so.

Nope, but it would make for great one shot adventures between a DH campaigns break points.

I'm really attached to playing an acolyte in DH. Starting off at the Uber power-level just seems like cheating to me now. It would be REALLY difficult to get me to stop playing DH completely just because another area of the 40k universe is out there to explore.

Plus, I've never gotten to play an arbitrator yet. That career is really appealing to me, but my cleric just won't die.... not that I'm trying to get him killed either.

I doubt that Deathwatch will supplant Dark Heresy. If anything, I can see group melding the three titles together for what could be a really intriguing adventure. I plan on merging my RT game with Deathwatch (still working on the details of how it's all going to happen) and I'm hoping the players will enjoy the merger.

Not for me and my players

 I run DH like a Call of Cthulhu game (w/ bigger guns) And I love CoC (and I am the GM)

I will run some DW games (like i do with RT) but I count on returning to DH and then maybe mixing them all together

 Nope......I will play them parallely, DW will be during a historical part of the Kuronous Expanse, a war the RTs accidentally warp-jumped past.

I would never see them as replacing each other. In fact I would like to mix them up as far as possible. I think if I like Deathwatch I'm going to buy Dark Heresy just for the stuff it could add to Deathwatch. (The character of my dreams would be a Space Marine Pariah. :D)

We moved from DH into RT when it came on board, but none of us would be ready to move on from RT by then, we are having way too much fun....   so our GM had the awesome idea that our RT characters would end up requiring a Deathwatch team to provide ahem "assistance" to us in our RT game... and that we could play both the RT characters and the DW characters...     of course this means our RT game is just going to get really interesting 

i think people will simply intergrate them all, since RT was able to work DH, so it goes to reason the DW will work fine with the rest, the group i play with mixed DH with RT and it is working out great

does anyone know if Deathwatch will be capatable with Dark Heresy? is character generation the same? I've been using the Adeptus Astartes unofficial fan made content to create a Space Marine so this book is particularly appealing to me to re-create that character with official rules.

Thanks

AFAIK, the only known comparison is that DW marines will be equivalent to Rank 9 DH (Ascension) characters in terms of power/stats.