I will say that the mere threat of stealth rocks being reflected back on their user will make pokemon leading with stealth rocks much more hesitant to immediately use them.
However, depending on how we decide to play gen 5 I think will play a huge role in what kinds of leads we will use. TheMaskedNitpicker made a really good point in his OP of the "End of Scouting" thread; since opponents likely will be able to see our entire team, it isn't nearly as reasonable nor as effective to have a team with one standard go-to lead, but rather multiple pokemon that can fill a leading role depending on the opponent's team. Of course, you can always play mind-games with this and use non-lead azelf/aerodactyl and lead with something else, for example, but that's beside the point. I think that "leads" like metagross, jirachi, and swampert will be much more prevalent than pokemon who tend to specialize in leading, i.e. aerodactyl, azelf, and ninjask (lol); I mean, who uses non-lead ninjask (who uses ninjask is probably the better question, though...). This encourages audibling who one would lead with, makes it less predictable to an opponent in terms of their own lead selection, and drives teams to have at least two pokemon who can lead that are able to, combined, take on a large majority of pokemon that might be used to lead. As a consequence, I'm not quite sure how effective espeon will be should "leads" decide to follow that path and be potentially multiple different pokemon, since stealth rocks on more than one team member seems redundant. That would mean that actually leading with a pokemon with stealth rocks might not always be used.
Eh, i just kind of clumped a bunch of different thoughts together. Hopefully things came out coherently.
[01:05] <DixieNormous> Rodan x pookar: Just Do It