Windows CE upgrades are provided by the hardware manufacturers. Most of the manufacturers have said that they will be providing upgrades, except for Philips. Only a few have given any timeframes for when upgrades will be available. This page will contain any information that I find about CE 2.11 upgrades.
C/Net has posted an article stating that LG Electronics and NEC have announced CE 2.11 upgrades for the Phenom and MobilePro 750C. LG is offering people who bought the Phenom Express a free upgrade up to January 15, the cost after that will be $129. NEC's upgrade will come in an upgrade kit and will cost $149.
Hitachi has posted on their upgrade page the availability of the CE 2.11 upgrade for the HPW-200EC in February 1999 for $100.
Compaq has announced upgrades for all of their C-Series handheld computers. The upgrade can be purchased for $109.
Available in late January, Compaq C-Series owners can order the Windows CE H/PC professional edition upgrade by calling Compaq DirectPlus at 1-800-888-9909 or by visiting Compaq's website at http://www.directplus.compaq.com/ProductLines.asp. In addition, in late January Compaq will begin selling new versions of the Compaq C-Series 2010c and 2015c handheld PCs with Windows CE H/PC professional edition pre-installed.
For more information on the ROM Upgrade, please visit Compaq's web site at http://www.compaq.com/products/handhelds/.
As of July 15, 1999 HP and NEC began shipping upgrades for their CE 2 devices. Upgrades for the HP 620/660 LX are available for $179. The upgrade for the NEC Mobilepro 750c costs $149.
For a tabular overview of the CE 2.11 upgrades click here.
If you own an HP 620/660 LX and are considering the upgrade check out Todd Ogasawara's upgrade article at his site. HP's offical 620/660LX upgrade page is here.
Unfortunately some hardware vendors have announced that they will not be providing CE 2.11 upgrades for their devices. These vendors include Philips who has stated that they will not be providing upgrades for the Velos. (Furthermore, Philips announced that they will no longer make any more Velo devices.)
Sharp has announced through a posting on the Windows CE City web site that they will not be providing upgrades for the Mobilon 4500/4600 line.