Sony Ericsson has been pretty quiet lately about the Xperia X1, its future flagship handset, giving no details about the official release date of the phone. Sure, the Swedish-Japanese joint venture stated that the device will hit the market in the second half of the year, but this could mean it can come in the summer or even in December. Well, it's neither of the two, it's September.

Handango, the well-known online store that sells mobile-related software and games, unveiled (probably unintentionally) the release date of Xperia X1, via an announcement that publicly informs us that they and Sony Ericsson are looking for mobile content compatible with the handset's display unusual resolution (800 x 480 pixels). Moreover, the "content" should also support several other languages besides English: Spanish, German, Italian and French.

While this release date (September) doesn't officially come from Sony Ericsson, we could say it's a semi-official announcement, hence chances are that the X1 will indeed come at the beginning of the autumn. Considering the fact that, a few months ago there were some rumors saying the device would not be commercially released until the first quarter of 2009, the September launching is obviously great news for all those waiting to get their hands on the first-ever Xperia phone.

The Xperia X1 already exists on pre-order, via several online retailers, for prices ranging from $700 to more than $1000. If you want to be sure you'll be among the first users to own the handset, you should probably make a pre-order and wait for September, when the X1 will knock on your door (not literally, hopefully).

We're waiting now for some details from Sony Ericsson to confirm the leaked release date. Most probably, these details will come pretty soon together with the real retail price of the phone.