Music enthusiasts are holding their breath. Cloud-based streaming service Lala says it will be shutting down completely on May 31, and credits can be redeemed on Apple's iTunes.

Ever since Apple bought the company in December, pundits have speculated that iTunes will soon incorporate a web-based music streaming service. It looks like such an announcement could come at Apples World Wide Developers conference June 7.

On Thursday, visitors to the site were greeted with a short message indicating the D-day and turning away would-be new users:

Current customers received an email encouraging them to hop over to iTunes. "In appreciation of your support over the last five years," the missive reads, "you will receive a credit in the amount of your Lala web song purchases for use on Apple’s iTunes Store. If you purchased and downloaded mp3 songs from Lala, those songs will continue to play as part of your local music library.

"Remaining wallet balances and unredeemed gift cards will be converted to iTunes Store credit (or can be refunded upon request). Gift cards can be redeemed on Lala until May 31st."

It's clear Apple wouldn't suggest users continue to make purchases if it didn't have plans for an iTunes-in-the-cloud offering. Such a service would likely allow iTunes users to stream any song currently in their iTunes library from any Apple device without requiring synching or downloading