The analysts who track Apple (AAPL) typically revise their estimates — usually upward — shortly before the company reports its quarterly earnings. But rumors that Verizon (VZ) might be stockpiling iPhones, and reports that Apple products are selling more briskly than expected this holiday season, have forced many to show their hands a few weeks early.

This week, several firms hoisted their Apple price targets — including Piper Jaffray (to $438), J.P Morgan ($420) and Kaufman Bros. ($395) — or lifted their line-item estimates by significant amounts. Among the most striking revisions:

• Kaufman Bros.’ Shaw Wu raised his estimate for Apple’s first fiscal quarter revenues by $1.12 billion
• J.P. Morgan’s Mark Moskowitz raised his Q1 iPad estimate by 1.27 million units
• Stifel Nicholaus’ Doug Reid raised his iPhone sales estimate by 1.05 million units
• Merrill Lynch’s Scott Craig raised his Mac estimate by 290,000 units

Details — with the most dramatic  jumps highlighted — in the spreadsheet below.

[Follow Philip Elmer-DeWitt on Twitter @philiped]