Are they being discontinued or just another model coming? If so what about the warranty on replacement?

If you buy one and break it, you can replace it over the counter and most shimano dealers free of charge for the same model if they have it. sometimes you are able to pick a different one if you want. If you go the route of sending it back to shimano, more often than not, you receive the same model back if they have any in stock or the newest model if it's out free of charge.  

 

I've heard they are being d/c from chat around the forums. 

The are on there way out, new model is coming at icast... this was confirmed by sft tackle when I called the other day

Here is Shimano's warranty - I own a Shimano V Rod that is over 10 years old, I contacted Shimano because the reel lock was going bad, they said to send it in and they would replace it with a Crucial as a warranty issue.  I didn't do it yet though because I love this rod, when the lock doesn't work I will probably replace it...but this thing is just the bomb.  (G Loomis designed this rod for Shimano)