The Financial Times claims that Silver Lake's buyout offer for Dell has gone to $15 a share, up from somewhere between $13 and $14.25, if a tablet-induced leveraged buyout can be put together.

Barron's thinks large stockholders are pressing for $20 and the Wall Street Journal says Microsoft's role in the affair is a "sticking point" and "one of several issues being hashed out ahead of a final buyout agreement."

Microsoft has offered to kick in $2 billion or more for equity in the form of convertible preferred securities to take Dell private and is expected to have a say in Dell operations.

The parties are evidently trying to figure how big a sway Redmond would have.

A sensitive point is how the investment would affect their commercial relationship, which doubtless troubles Dell rivals too. Apparently Microsoft envisions the lion's share of Dell's devices being Windows-based.

The Journal's sources still believe the deal is "on track" and could be announced in the next few days.

The deal would include Michael Dell's 16% position, $15 in debt financing arranged by Silver Lake with at least four reported banks, and equity contributions from both Microsoft and Silver Lake.

Reuters says there's a Plan B in case the buyout falls apart: Dell would do the borrowing and buy back a lot of shares but such a path wouldn't solve the basic problems a buyout is meant to address.