Android doesn't seem to have a set limit.
If your phone is getting slow, check the memory you have and go from there.
Regular maintenance is needed just like your BlackBerry.
There is an article on the main page on this.
One person posted that he was out of memory for Apps. He said he had something like 99 apps installed. One of the neat things about Android is you can uninstall an app, and reinstall it if you need it.