the cabin, Kelvin, the smoke monster, the emergency hatch, the glyphs, the temple, the magic water, sayids zombie condition, sequence if numbers to be input, the statue, ilanas past with Jacob, why the others dressed up, miles ability, the wheel, etc were nothing more than a series of macguffins. Now it is clear the writers just saw them as kewl high concepts,,,mere passing ideas,,,not something to use, develop or explore further in any interesting or dramatic way. Sadly that seems to be a trend,,,writers cramming a billion ideas and teasers into a series and leaving them by the wayside rather than choosing a few and taking the time to develop them. I guess they just don't have the writing skills of their predecessors who realized quality over excess is much better.
seems like poor writing to introduce all these mysteries and have the characters draw attention to them making a big deal about it then not do anything with it. Usually when you point something out it will be addressed or play a role in things to come. Season two was particularly bad about it.