A report has surfaced that suggests Apple CEO Tim Cook was spotted at Valve's Washington head office, fueling more speculation that Valve are looking for partners to work with for their long rumoured entry into the console market with a machine dubbed the ‘Steam Box'.
The report in Cult of Mac suggests that they have sources that think Cook did meet with Valve, and that Apple are planning on joining the console market with a machine of their own.
At this point the link between Apple and Valve should be considered pure speculation, even if it did happen they could've been talking about something completely different. It does, however, follow on from recent speculation surrounding a job posting by Valve. These rumours are getting persistent now.
On the other hand, it was recently revealed that Valve are working on new hardware; wearable computing. Perhaps that is what Apple were in town to take a look at?