PHP upgrade – Plesk

Hi

i have a load of WP sites running on a dedicated server – I administer it via Plesk v9 –
I am having to upgrade Plesk to the latest version which will in turn upgrade my PHP from version 5.2.4 to 5.3
My question is, will my WP sites still work with the PHP upgrade.

Looking forward to your reply.

Many thanks in advance for your help.