I assume that the core TrueType fonts like Times New Romand and Arial will be supplied with Windows 10. Does anyone know if there will be new fonts supplied with Windows 10?
Just a recent announcement. They're catching up with OS X, or saying that they really should have made us pay for 8.1.
Before, there was a rumor that the version after 8.1 wouldn't be called "Windows". There was a thread with people joking about what they could call it instead. I suggested "Standard", after all, it's what people buy because almost all the third-party software is made for it.
But even the name "Akzidenz Grotesk" is taken. Well, there you are. They should include that as a replacement for Arial.
That brings me to another font: Calibri. According to Lucas de Groot he initially proposed a version without rounded corners. MS chose the rounded version instead. Why? One of the most given critique of Calibri is that it looks "childish" because of the rounded edges.
De Groot redesigned the font, taking out the rounded corners. When submitting the proposal to Microsoft, he sent along a sample of the original version, adding: ‘I like the look of it, but as you see these rounded tops look real ugly in ClearType; don’t choose this.’ De Groot had in fact been critical of the ClearType rasterizer when he first saw it demonstrated.
To his astonishment, Microsoft chose the rounded version.
Also to my astonishment... Anyway, can we expect a Calibri without rounded corners? Maybe as an OpenType feature? Lucas de Groot already designed the font without rounded corners, so it might cost half the effort. Just sharpening the edges would not cause reflow issues. Besides, Windows 8.1 also came with another Calibri variant, Calibri Light.
Sylph, I see one problem with marks being too far left on some bases in Calibri, but no problems with the other fonts you indicated.

Also tested italic, bold and bold italic fonts, with same results.
Font versions tested, in Wordpad, Windows 7:
Calibri v5.72
Cambria v.5.96
Segoe UI v5.05
Arial v6.82
Captured from web.archive.org on 18 Apr 2015. view this capture
The sharp Calibri definitely looks better. I'm tired of seeing the rounded Calibri in very inappropriate contexts. A sharp Calibri is some progress already. At the art academy I'm at you can almost guarantee students will use DIN. If not, they usually don't care enough to change the typeface to something original at all and they go for the standard Calibri. Last week I saw it in a digital presentation where it was practically used as a display typeface. I got really frustrated seeing that. Calibri is a nice typeface, but it seems packing it with Windows inevitably leads to abuse of the typefaces. I'm actually surprised people at the academy aren't typographically versed enough to make an appropriate choice in typeface. They never really seem to care. Well, they're starting to discover Gotham now. They're late to the game but they will inevitably follow trends while they're supposed to think about their type choices.
Anyway, I see the sharp Calibri has bigger counters. That's good. I sometimes use Calibri in Word when I need to type out something before putting it into InDesign and I always felt the counters are too small. Especially with the rounded edges, the /a in particular looks very small.