To my mind, the mid-to-late 90’s were largely (though hardly exclusively) about fiddly, rules-medium-to-heavy systems. In the earlier part of this decade, D&D 3.5 and Exalted weren’t Rolemaster or HERO System, but neither were they Risus.
It definitely seems we have seen a swing in recent years more towards simpler mechanics in games. That’s not to say there isn’t room for Pathfinder or FantasyCraft, but at least online I tend to see more and more gamers (including yours truly, a grizzled Rolemaster aficionado) espouse the virtues of rules-lighter games. Of course, we’re all getting older, aren’t we? We don’t have the time (we think) to master the volumes of rules we pored over when we were in high school or before the rugrats came along.
Yet I wonder…will the pendulum swing the other way again? Will complexity return as the online tools to manage it become more an accepted part of our tabletop experience? It’d be interesting to see a Rolemaster resurgence, as thousands of players again discovered the joys of massive critical hit charts and Tripping Over Invisible Turtles.
I think if more rules-heavy games surge again (not that they’ve ever completely gone away), it will be because of computer aids or electronic products that automatically handle that complexity. We already have spreadsheets and some products that do these things—I think when they become an expected part of the game, rather than an exception for most groups, you’ll see some of the common complaints of rules-heavy systems (“they’re too hard to learn, they’re too complex for newbies, resolution/chargen/anything takes too long”) will fade away. There’s no reason that with the right equipment and/or personnel our complex rules systems can’t be run just as quick as rules-light games. The amount of time we have to game may lessen gradually as we get older, but the tools to maximize that time are promising indeed.