I got a tourist visa from Laos and then extended it for 30 days at Laksi. The extension stamp runs out in another 9 days.

But the visa states "No. of entry 2". and "Enter before 30 Sep 2010". Does this mean I can just leave the country and come back in for another 60 days?

(Also I'm assuming we are now only allowed 2 tourist visas in a given time frame, is this right?)

You must enter before 30 September to get the new 60 day entry and you can extend that another 30 days.

How many entries are allowed on a tourist visa is up to the Consulate - but most locally will limit it to one - Vientiane is an exception in the area.

Yes, you can leave and re-enter before the 30th and get another 60 day stay, that can also be extended for an additional 30 days. Some consulates may limit the number of Tourist Visas they will issue, but there is no limit by regulation.