Sprint-Nextel ( S ) this afternoon said it formally requested of the Federal Communications Commission that it block AT&T’ s ( T ) proposed $39 billion takeover of Deutsche Telekom’ s ( DTEGY ) T-Mobile U.S.A. unit, stating that “anti-competitive market control” would be the outcome of such a union, and that it’s the FCC’s job to protect consumers from such

This is a busy week for chip and computer watchers, with the mammoth Computex trade show going on in Taiwan. For Qualcomm ( QCOM ) fans, it’s double the excitement with the company’s “ Uplinq ” conference in San Diego, taking place tomorrow and Thursday .

The Globe & Mail’s Paul Waldie and Body Erman posted a video this morning asking if Research in Motion’s (RIMM) co-CEO Mike Lazaridis should go. (A video preceded, I would note, by an add for the BlackBerry PlayBook tablet computer!) The question, as framed in the video, is whether the top “nerd,” Lazaridis, must go because he’s not “putting out the product.” Lazaridis shares the CEO role with Jim Balsillie , regarded more as the marketing/financial person.

Estimates are starting to trickle in for what Nokia’s ( NOK ) cut in forecast this morning actually translates into.

Engadget’s Terrence O’Brien this morning speculates that a new version of Research in Motion’s ( RIMM ) “PlayBook” tablet computer with 4G wireless links could be on the way for the summer, as expected, based on Google search results for the phrase “ Sprint PlayBook .” Such as search comes up with links with provocative titles such as “Sprint | Introducing the BlackBerry 4G Playbook Tablet,” although said links actually lead to nondescript pages.

Citigroup analyst Walter Pritchard this morning initiated coverage with a Buy rating on shares of SourceFire ( FIRE ), the maker of computer network intrusion prevention software and hardware, writing that the explosion of mobile devices is increasing the need for “countermeasures” in cyber-security. The competition, Cisco Systems ( CSCO ), Juniper Networks ( JNPR ), and McAfee , which Intel ( INTC ) just bought, is distracted, he writes: “Leader Cisco continues to have challenges and Juniper appears incrementally more network-focused.

And you thought LinkedIn ( LNKD ) was fantastically overpriced? The Financial Times’s April Dembosky yesterday wrote that Facebook investor and PayPal co-founder Peter Thiel thinks LinkedIn’s underwriters, Morgan Stanley , Merrill Lynch , and JP Morgan drastically underpriced the company’s IPO two weeks ago, which seems plainly evident given the stock price today is at $85.80, 91% above the $45 IPO price the banks set.

Apple made a pretty steep climb at the open following word CEO Jobs will head the company’s June 6th developer conference. Apple ( AAPL ) shares are getting a substantial lift here this morning from the announcement a little while ago that CEO Steve Jobs will help unveil “next generation software” during the company’s Worldwide Developer Conference on June 6th in San Francisco, starting at 10 am, Pacific. The stock is up $5.94, or 1.8%, at $343.35

The Washington Post’s Michael Rosenwald this morning pens an interesting piece about how the federal government, under CIO Vivek Kundra , is letting more and more government workers choose their own gadgets of choice, rather than impose on them use of government-specified devices. Although a number of anecdotes come up in the piece about Apple’s ( AAPL ) iPhone and iPad , and Google’s ( GOOG ) Gmail, the article is titled, somewhat more pointedly, “Federal government loosens its grip on the BlackBerry ,” meaning, of course, the traditional use of Research in Motion ( RIMM ) messaging devices

Auriga Securities analyst Sandeep Shyamsukha this morning initiated coverage of Nvidia ( NVDA ) with a Buy rating, up from the Hold rating that had been maintained on the stock by Shyamsukha’s predecessor, Daniel Berenbaum, who left the firm this month.