FUD Zilla reports leaked slides reveal Intel plans to get rid of the Core m5/m7 names. Instead, the Kaby Lake family will shake things up by using Core m3/i5/i7 naming for the laptop parts. The site speculates that things may get a bit confusing, as it appears that some Core i3 processors will probably offer more performance than other low-power Core i7 processors.
Kaby Lake will get USB 3.1 generation 2 support as well as enhanced integrated graphics. Here's a bit of information about the Y and U series parts:
Kaby Lake-Y will have 4.5 watt dual-core chips with Intel HD 615 graphics, the Core M3-7Y30 will have a 1 GHz CPU w/2.6 GHz turbo boost and 300/900 MHz graphics, the Core i5-7Y54 will have a 1.2 GHz CPU w/3.2 GHz turbo boost and 300/950 MHz graphics, while while the Core i7-7Y75 will hae a 1.3 GHz CPU w/3.6 GHz turbo boost and 300/1050 MHz graphics.
The Kaby Lake-U gets 15 watt dual-core chips with Intel HD 620 graphics, the Core i3-7100U has a 2.4 GHz CPU with 300/1000 MHz graphics (turbo boost N/A) and the Core i5-7200U has a 2.5 GHz CPU w/3.1 GHz turbo boost and 300/1000 MHz graphics. Lastly the Core i7-7500U has a 2.7 GHz CPU w/3.5 GHz turbo boost and 300/1050 MHz graphics.