I'm a July 2011 applicant, out of country. Are you a type 175 or an 885? If you're an 885, they're already up to 30 May 2011. In-country applicants seem to be staying about 5-6 months ahead of out-of-country on CO allocation. If you're a type 175, then you'll probably want to wait until they're a month or two away from August.
June was a very "fat" month for applications since a lot of people tried to get in under the old points system. Basically, when I see they're allocating June 2011 applicants, I'll schedule meds. Technically, you take a risk until they're requested, but I feel comfortable making the move at that time. I'll have to travel a few hundred miles to get them done, so I'll need some time to plan for that trip. I live in the US, and those checks from the FBI takes two to three months, so I'm probably looking at ordering Police checks in a month or two. I'm looking to make the move fairly soon after I get my grant, so I'm not too worried about them expiring.