First off: I must say your army is truly an inspiration to me and if the site lets me I shall sling my full +rep prowess in your direction. It still amazes me that you have managed to take my least favorite chapter ever (Blood Angels) and made them into something that blows my Space Marines out of the water.
Speaking of space marines...and water...I had an input idea for your next chapter.
This may be a bit biased due to my own opinions, but...Space Sharks!
You have the best of numerous worlds:
1. With Imperial Armour 10 on its way, you're sure to get some Sharky recourses sooner or later with which to draw upon (rules, conversion packs, etc).
2. You can appeal to your convertive side with some little mods here and there that add some flavor to the minis (for example, I added sharktooth necklaces, fins on my commanders, etc).
3. You appeal to your inner geek of yesteryear by remembering the good ol' days of Rogue Trader and the original Badab War supplement.
4. With their murky grey/white/red scheme you can experiment with colors while still remaining in your area of expertise.
4a. Rogue Trader-era Camoflague! You know you want to!
And finally 5: We all know how awesome sharks are. But in SPACE?!?!?!??!?! SHIT GETS REAL!!!!!
EDIT: Some motivation:
Space Sharks in IA10:
Space Shark blurb:
IA10 Space Sharks quote:
"We surrender...by the mercy of the God-Emperor, the war is over...we have surrendered...."
Final Vox-Intercept, Void Colony Sigurd VII