Hey,
Dnt worry abt it.. they are recruiting like crazy now and we are also moving buildings/HQs within Dubai so it's a very busy time at Emirates. You'll get your letter very soon. Should get it within the next 2 days or so.
Also expect delays when it comes to approval of medicals and all that... Just make sure u do everything they ask u to accurately according to their instructions and processing your application will also be easier on their part.
Congrats by the way.. U r very lucky and I'm sure u'll be very happy when u get here. It's all worth it.