since we already saw that photo what, a week or more ago? We know Shane dies, no big surprise there.
If this turns out true, there's only one aspect I like about it - that Rick would trick Shane to get the upper hand and kill him. That at least gives a little interesting character development to an otherwise obvious way to kill off Shane - gee, he wants to kill Rick and Rick beats him to it. Not particularly dramatic.
That lack of drama isn't only thing I don't like about it - there's also the lack of drama in Carl shooting a zombie Shane. Yea, he gets some redemption for not shooting another zombie that ends up killing Dale, but it isn't a particularly dramatic or shocking moment.
And finally, if they are going to have zombies overrun the farm, they better do it well. I'm not imagining a way that works for me - one gun shot isn't going to draw a massive horde, so they already must be a massive horde, and they just happen to stumble on the house at this most inopportune time? And even though we've seen hordes move through other areas (like on the road), this horde doesn't keep moving on if they lock themselves up tight in the house? And somehow they manage to escape the horde anyway with most of the folks alive? The whole thing is just to much of a reverse deus ex machina.