Yes - The More the Merrier!
No - The Pool is already Too Crowded!
That's a strange definition of "a lot" and "recent". (Edit: Although rumor has it they are next after IG, so expect some new stuff for them soon.)
But of course the better example is Sisters of Battle. Yes, they got a digital "reprint" of a WD codex with minimal tweaks. I would buy 3-4 boxes of plastic sisters in a heartbeat.
If you condensed all of the Space Marines into one book, you'd have more than enough room for at least one more xenos or chaos army!
It's purely selfish, but I want Slaugth. I think they are the coolest aliens in 40k, and a little more innovative compared to most others - they have a nice mix of classic folklore esque grittyiness mixed with clive barker and lovecraft esque horror, far scarier than Dark eldar, chaos or nids IMO. I can almost visualise the plastic kits in my head if I try hard enough - those horrifying constructs in multipart duel kits and the Slaugth themselves as character mini-sprues.
One of the big problems GW has with independent retailers, is the size of the product line. What would be cool has to run up against things like "What will fit in the stores" and "Can retailers afford it".
And, as mentioned above, there is the issue of whether GW can even support their existing armies.
I think GW ought to stick to what they've got for awhile, and leave possible new factions as small scale forgeworld experiments for now.
Anuvver triumph uv orky know-wotz!
Hmmmm, I voted "more please" but now I'm trying to think what group the new army would appeal to.
We have the obligatory Orks, Eldar (Elf) and Humans for the staunch purists and fantasy lovers.
Dark Eldar for the Emo crowd.
Sister of Battle for the frustrated guys.
Necrons for the Goths.
Tao for the Anime people.
Tyranids for the animal lovers (Think about it, it makes sense).
Chaos For the Evil at heart (you know who you are).
And many many flavors of Space Marines to cover the Vampire/Werewolf crowd, the human EMO scene, the holier-than-thou players along with enough leeway to make your own themed army if none of the standard groups float your boat!
Sooooooo what group are we leaving out?
The Jock? Nah.
The Super Nerd? They are getting Adeptis Mechanicus in 30k.
Preppies? Um, no.
I think if we answer this question we will have our new army!
So, what do you think needs to be represented in 40k?
Forge World has stated that they're going to do the Dark Mechanicus, if that counts.
After that, I think GW really needs to concentrate on fleshing out the factions that they already have, probably through more minidexes. There's so much more that could be done with just Kroot alone (thunderlizard cavalry, a pterodactyl-like flyer with a howda on top for crew, unique HQ options, etc.). GW has really barely scratched the surface of their own IP.