Why no Olympus "pro" standard zoom

my take on this is that Oly , with E-M5 being weatherproof body and only 2 weatherproof lenses, will/should introduce more lenses with weatherproofing. probably one tele zoom to complement 12-50. it would be nice if they make a set of faster zooms when they introduced upper tier OM-D body

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my gear:
E-M5+45mm/1.8
E-520+12-60+14-42+70-300+Sigma 105 + FL-50R+EC20 + SRF-11
and good number of legacy lenses (list in profile)