Multi-core CPU - We are told that Nokia is already testing dual-core phones, and other brands will follow suit soon. Moreover, these high-end devices will have nothing less than 1 GB of RAM.
MicroSD card slot - The lack of microSD card slot was one of the biggest downers on Windows Phone platform. Thankfully, it has been added to the Apollo.
Pixel packed screens - Moving on from pixel dimensions of 480x800, WP will now have pixel-packed screens. Yes, it's not wrong to expect 720p screens.
New camera API - A new camera development kit means that manufacturers will now be able to customise the camera UI and features at their end. Yes, this will help Nokia bring the PureView tech to the Lumia series.
NFC - Although Nokia has already included NFC to Lumia 610, Microsoft will now offer NFC support directly into the OS.
Skype integration - As speculated by most enthusiasts, there will be deep Skype integration.
Demise of Zune - Microsoft is pulling the plug on Zune for good. Copying you songs and video will be taken care of using the MTP (Media Transfer Protocol) mode.
Bluetooth (FTP) - Since Microsoft is unlikely to add a Bluetooth file-sharing option to the platform, Nokia is working to bring this option via an exclusive app.
Minor UI tweaks - Don't expect to see any radical change in the user interface, as Microsoft wants to keep it simple. However, users will be given an option to use tiles of different sizes. Here's a mockup image that I've made, based on the basic of information that I have.