Nokia has created a very useful webpage for software update availability. You can find details such as what the update brings in, device ROM versions that will get the update, availability region, etc,. For example, the upcoming update for Nokia Lumia 800 and Lumia 710 that brings enhanced experience included the following,
Internet Sharing (Wi-Fi Hotspot)
Share your mobile internet connection over Wi-Fi with up to five client devices or computers.*
Flip to silence
Silence incoming calls by flipping your phone face down.
After updating, your Nokia Lumia 800 or Nokia Lumia 710 will be ready to install exclusive new applications available in the Windows Phone Marketplace (Camera Extras, Counters, Contact share, PlayTo and more).
More information on the upcoming Lumia updates can be found on the NOKIA Website by clicking here.
Phones in question: NOKIA Lumia 610 and 900 will get updates soon (some already have) and Lumia 710 and 800 expected in July.