Good News! Adam Lambert is vying for his first No. 1 album on the Billboard 200 chart next week.

Bad News: His "Trespassing" set may only sell around 70,000 to 80,000 copies by the end of the tracking week on Sunday, May 20, so say industry sources. It could mark the smallest sum at No. 1 on the chart since last August (chart dated Aug. 20), when Adele's "21" sold 76,000 in its 12th nonconsecutive week atop the list, according to Nielsen SoundScan.

But don't break out the bubbly just yet. "Trespassing" may be blocked from the top slot next week by either Carrie Underwood's current champ, "Blown Away," or Adele's "21." Both albums could sell perhaps 65,000 to 75,000.

The new Billboard 200 chart's top 10 will be revealed on the morning of Wednesday, May 23.

Lambert, who finished in second place on the 2009 season of Fox TV's "American Idol," saw his first major label studio album, "For Your Entertainment," debut at No. 3 later that year with 198,000 in its first week (according to SoundScan). The album was released during the very busy Thanksgiving shopping week and was blocked from the top slot by Susan Boyle's "I Dreamed a Dream" (a debut at No. 1) and Andrea Bocelli's "My Christmas" at No. 2.

To support "Trespassing" this week, Lambert played ABC's "Good Morning America" on Monday (May 14) and is scheduled to perform on "American Idol" on Thursday (May 17).

Other albums on course for notable debuts next week include the "Glee - the Music: the Graduation Album" soundtrack, Tenacious D's "Rize of the Fenix," Beach House's "Bloom" and Garbage's "Not Your Kind of People."