Neowin posted some info on Windows 10 Mobile build 10158

Windows 10 Mobile build 10158 has been reportedly released to some of Microsoft’s developer partners and it features a bunch of changes compared to what’s publicly available. As you can see in these screenshots there’s some obvious UI polish present, but that’s not all. According to the leaker who shared to images this are other changes found in this build:

Smoother and more responsive than 10149
Windows Store seems to be final as BETA tag is removed
Windows Store now has transparent tile
Microsoft Edge now has transparent tile
New animation for People live tile
New version of the Wallet app

  Windows 10 Mobile build 10158 info and screenshots leaked