Note: Please bear in mind when I read these thoughts that I am still two installments (Blackest Night #4 and Green Lantern #47) behind in Blackest Night so if the situation has changed that dramatically, you don't need to spoil it in the comments.
I hate to admit this, but as a Kyle fan Blackest Night has me worried.
Rebirth didn't really worry me because it started with his narration, and he was the first Lantern seen in the miniseries. It turned out to be a pretty damned good portrayal of Kyle, even though it sadly signalled the end of him narrating every appearance he makes. I still miss Kyle's narration a bit. I'm convinced he's still completely neurotic underneath the Model Lantern exterior. Some of the interaction with Guy (He was shocked to actually be respected by Captain Comet and only shows this when talking to Guy; He's overthinking what he saw in the Star Sapphire and only lets Guy know this) supports this, and if you reread Kyle as written by Ron Marz or Grant Morrison without looking at the narration you can see the behavior is the same.
The Sinestro Corps War didn't worry me at all because it started with him getting kidnapped and possessed by Parallax. This was not only living what was arguably his worst fear (after years of being cautioned not to let power go to his head and go bad like Hal, the exact same thing that happens to Hal happens to him), but it was the beginning of a story that was definitely going to end with him freed in some way and returned back to a regular Green Lantern and not some silly creature with near omniscience who can't really do anything effective. I gave Ion a shot, but he's preferrable this way. And since then Tomasi's written of the best Kyle stuff I've seen in a long time.
Blackest Night worries me. I don't think for a second they'll kill Kyle off or even turn him a different color. Hell, I'd lay down money that if every other Green Lantern turns color once during this crossover, Kyle will remain green unless the entire multicolor company turns white at once--in which case he'll go green-white-back to green at the end. I wouldn't be very surprised (but I would be greatly amused) if there was a point where he was actually the Very Last Green Lantern again, after everyone else (including Hal, because there's a good chance he's turning yellow before this thing ends just to give Indigo-1 a headache) has ended up involuntarily switching colors due to all the chaos being thrown around here.
But I'm worried I'm not going to get what I like best out of a Green Lantern crossover here. I'm looking at the storylines in Green Lantern Corps and Blackest Night/Green Lantern, and I see two storylines that aren't going to merge before the climax. The other two? Both Kyle and Hal were set on a collision course from the get-go, because part of the plot was one had to find the other. This one? Hal's gone questing while Kyle defends Oa against the Ex-Girlfriend from Hell (and the other forces of Death and Destruction, but really she's pretty imposing here). Hal's teaming up with other emotionally scarred Silver Age alumni like Carol Ferris and Sinestro in adventure therapy. The climax there is Hal and company getting enough understanding to work together. One that's done, returning to Oa and teaming up with Kyle and Guy will be a formality and part of the resolution. In the other two crossovers, saving one of those two was the climax and everything after that (after Hal's return in Rebirth and Kyle's rescue in SCW) was the formality and part of the resolution.
Really, what I like best about Geoff Johns' Green Lantern crossovers is the Hal and Kyle teamup. We very rarely see these two fight side-by-side apart because that's something saved for special occasions. And it's not the same if its just them in a big battle scene with everyone involved. It's not the same quality of interaction we had in the first two installments of this huge megastory Johns has been writing. As awesome as it is to have Carol back as a major character (and holding her own against Sinestro, and being the wisecracker in the questing party), I'll be a bit disappointed if the mainbook's storyline doesn't merge with Oa's at least in time to get a moment between my two favorites.