So far every site "leaks" about the same info which is known for months. This is why i decided to summarize all the info I gathered through my sources at Apple and various trustworthy websites and people.
1. iPhone 5 will have round (3G, 3GS like) back. Very similar if not the same as the chinese iPhone 5 clone seen in the following picture.
2. iPhone 5 will have new A5 CPU - it is know to be next generation Cortex A9 Dual Core CPU - contains much faster dual-PowerVR SGX 543 graphics processing unit, and generous on-chip DDR2 memory.
3. Better camera - it is known that iPhone 5 will have Omnivision OV8820 sensor. It is 8 megapixel and capable of recording 24 or 30 frames per second on 1080p.
4. Qualcomm GSM/CDMA chipset - more energy efficient than the Infineons used today. Exact model of the cihipset is still unknown. LTE will not be supported by this chip. LTE support will be included in later model of iPhone
5. Larger(rumor) and faster(not rumor) flash chips - I heard that they will include latest Toshiba chips in iPhone 5 (which is a rumor), and largest iPhone 5 model will have 128 GB of memory inside.
6. Tottaly redesigned antennas - they have learned a painful lesson from iPhone 4
7. Display - IMO it will remain the same. Apple is testing new technologies Super-AMOLED and something that they call "Next Gen Projection-Type Displays" . Also they invest in Toshiba and Sharp factories as their new diplay suppliers. Also they will continiue to use LG for displays as well becuse they have 5 year contract which expires january 2014. Apple will remove the home button in a future iPhone model which will make the screen reach 4 inch.
8. Software - right now Apple test iOS 4.3 on iPhone 5, but it will not be shipped with it for sure. iOS 4.3 will be out in March for the supported devices. Most likely it will recieve later update of the OS considering it will ship at best in August 2011.
In 2011 there will be 4 versions of iPhone and 3 versions of iPad. Two hardware versions of iPhone 5, 2 more hardware versions of iPhone 4 and 3 hardware versions of iPad 2. About iPhone 4 versions one is the Verizon iPhone 4 and the other is revised iPhone 4 without any antenna issues. The iPhone 5 models will probably one GSM only model and one GSM/CDMA model. There will be 3 Versions of iPad2 as well - one Wi-Fi model, one GSM model and one CDMA model - both like iPad 3G but for difrend networks.
iPad2 brief news - basicly same changes apply there as well, A5 CPU, higher resolution and DPI display, but not near RetinaDisplay DPI. Apple will probably make it Retina in next ipad.
First i heard from a friend about iPhone 5 was that it will be a refresh model like a 3G and 3GS, but after i have found out the specs it will be more like a huge hardware upgrade.