back on point - there's an important aspect of AF that you won't learn from reading reviews - for sports work it's important how good the AF TRACKING is. Most reviews that talk about AF are refering to single shot performance - ability to lock on a target and get one shot. That is only part of the puzzle. As for the E3 being the fastest - that claim is from Olympus. The reality is you're not going to see a single Nikon D3, D700, D300 or Canon 1-series or 50d sell off their gear to buy an E-3 and expect better focus performance. So far I haven't seen anything from an E-3 user in the sports field that competes with the shots the Canon and Nikon folks are getting. To be fair, that's mostly because sports shooters primarily flock to canon & nikon. So the challenge for Oly is actually attracting accomplished sports shooters to use the E-3 and prove it out in the field. But, as of now, I've seen nothing that says the E-3 is in the same league as the above cameras in the field for sports shooting purposes.
Every manufacturer makes marketing claims - I wouldn't pay them much heed. The great thing about photography is you should be able to see for yourself. The reality is, the OP isn't considering cameras in the E3 range. And no, Olys cameras below the E3 can't compete focus wise with canon or nikon, not to mention high ISO wise. If the OP is intent on sticking with budget lenses, the Pentax is probably better option than Oly or Sony at the low model level. And without the right lenses the better af performance of the canon won't be fully realized.