19 are available from the Extras. If you include what is coming down the pipeline in the very near-term (Extras-testing / Extras-develop) the total is close to 80. Its a matter of time when the numerous and diverse Maemo 4 apps are ported to 5.

Keep in mind Ovi Store for Maemo 5 is also in the works and will most likely be online when the devices are officially shipped.