Thanks to leaked slides earlier in the year, it's been known to many for months that Ivy Bridge can handle driving three outputs at the same time, compared to two outputs on Sandy Bridge and other previous-generation hardware. With the publishing of several patches to Intel's DRM (Direct Rendering Manager) kernel driver, this IVB feature is further confirmed and new details revealed.
The "official configuration" for the Intel Ivy Bridge triple monitor support will be for driving three DisplayPort outputs. Yes, so we'll be seeing some Ivy Bridge motherboards (likely the higher-end models) bearing three DP ports. But that won't be all, as it looks like (based upon comments from the Intel developer working on this Linux driver support) there is also pre-production hardware with dual HDMI and VGA. There will also surely be other configurations available of multiple HDMI and DisplayPort connectors. Due to the limited real estate at the rear I/O panel, it will be interesting if motherboard vendors opt for mini DisplayPort connections with these new 7-Series "Pather Point" products.
A limitation of this triple monitor support for Ivy Bridge is that two of the pipes need to share a PLL. Ivy Bridge has three planes, three pipes, three transcoders, and three FDI (Flexible Display Interface) interfaces for this triple monitor support, but there's only two pipe PLLs. This means that two of the three outputs need to have the same connection type and same timings. However, most people in a triple monitor environment will have at least two -- if not all three -- of the monitors be identical and configured the same, so this shouldn't be a terribly huge issue.
The patches enabling this support in the Linux driver haven't yet been pushed to Git, but are currently floating on the intel-gfx list for review and until the Intel developers have tested this work with more of the new hardware configurations. Hopefully this will be tested and ready to be merged into the Linux 3.2 kernel.
As mentioned already, the Intel Ivy Bridge Linux support appears to be in good shape. There's been code available in the public for the xf86-video-intel DDX, Intel DRM, and Mesa drivers for months (going back to April). All of the key support appears to be in place and now the OSTC developers are tackling other areas (e.g. the triple monitor support) and other performance optimizations for Sandy Bridge and Ivy Bridge. Intel Linux developers, off the record, have also commented to me that the Ivy Bridge Linux support is looking really great.
It's quite nice to see that there should be good "out of the box" Linux graphics support for Intel Ivy Bridge hardware when it's released in a few months, but let's hope there aren't any last minute snafus like there was with Sandy Bridge on Linux or motherboard vendors breaking things with odd configurations. Intel also hopes to finally have OpenGL 3.0 support on Linux by that point.
Ivy Bridge CPUs and Panther Point motherboards are expected to be released in early 2012. Among other features of the Sandy Bridge successor are PCI Express 3.0 support, even better graphics performance than SNB, reduced power consumption, and USB 3.0 is integrated into the Panther Point chipsets.