Little or none, said Michael Silver, an analyst with Gartner.
"There's a good chance that 10% or 15% of organizations' PCs will still be on XP after support ends," said Silver in a Wednesday interview. "That wouldn't be atypical, actually, for a Windows operating system."
Forrester's Johnson said his firm's numbers were similar, although it posed the question differently to enterprises.
"We asked 'What are you deploying now on new PCs?' and enterprises are saying the 76% are deploying Windows 7. But 16% are still going with XP," said Johnson.
"When we ask them what they'll be deploying 12 months from now, their answer is Windows 7, with 60%, Windows 8, at 26%, and Windows XP, 3%," Johnson continued. "But enterprises are notoriously optimistic about future deployments, so I'd say that by the time it reaches retirement, XP will still be on 15% to 20% of PCs."
That's actually lower than projections run with Net Applications' data, which estimates the percentage of PCs worldwide running each version of Windows. If the trend tracked by the measurement company over the last 12 months holds true going forward -- not a certainty; XP's decline has accelerated in the past year by about 8% -- more than a quarter of the planet's PCs will be running XP in April 2014.
Now that's staying power.
But not a smart strategy for enterprises, Johnson and Silver said.
"If they haven't started migrating from Windows XP at this point, they're far behind," said Silver. "They need to get their act together."
Both Gartner and Forrester have recommended, and continue to recommend, that organizations still running Windows XP migrate not to its successor, Vista, or to the brand-spanking-new Windows 8, but to 2009's Windows 7.
"There's safety in numbers," Silver noted. "Would you rather be on Windows 7, where everyone else is, or with the 20% of those running Windows 8 [in 2014]?"
The two research firms have urged the XP-to-Windows 7 migration on clients for over two years, once it became clear that the latter was stable, successful -- meaning it would be widely supported by third-party developers -- and secure.
Microsoft has said exactly the same, although that drumbeat, once loud, has quieted considerably as Windows 8 moved towards final.
But as Silver said, firms that have left things to the last minute may be in for a world of hurt. "If [an enterprise] hasn't made any progress toward Windows 7, the time to test, verify and move from XP in just 18 months, well, that has a low probability."
Even a year after the 2014 deadline, up to 5% of enterprise PCs could still be running XP, said Silver. Among the worst offenders in that potential camp: health care.