I myself don't think this theory is amazing, nor have i put that much thought into it, but i thought i would share it for some fun :)
Basically twice this season (Maybe more?) has a character been sentimental about the original crash of 815. Ben in "Dr Linus" says he remembers the crash like it was yesterday. And Jack in "The Package" says it seems like a 100 years ago the plane crashed (He also mentions this to Kate in "The incident" although she corrects him saying 30 years from now).
This gave me a thought that perhaps the timeline they are now in IsNT actually 2007. There had been speculation about this before seeing as ajira 316 took off in 2008 (But we already know the island goes at a different time to real world). So i thought maybe they are actually far in the future (jacks remark 100 years) or they could even be back in early 2005 (espically as we never saw any time on the island in 2005 - 2006 as they were in Dharma)
Just a small thought, Thanks for reading :)