Every year, like the fireflies, they emerge with the gathering heat of summer. Even as the more established sophomores hobble out of the Triple Crown series--many requiring rest or recuperation, some even menaced by retirement--a second wave reliably reinvigorates the crop. Sure enough, in recent days a couple of new names have volunteered themselves to test the resilience of those Classic protagonists who do persevere to Saratoga and beyond. But while both share a fresh, progressive profile, in other respects they could scarcely be more different. 'TDN Rising Star' First...