LB is becoming more prominent now as a position being looked at by the Pats. The lack of DT's is very interesting. either there is no interest (my belief) or they have one name in mind and they don't want to telegraph anything (Jesse Williams perhaps?)
Further to this point and thinking from the perspective of our first and second round picks from previous years:
The following DE and Safeties visited in 2012:
OLB/DE: Bruce Irvin, West Virginia - V
OLB/DE: Melvin Ingram, South Carolina - I, APD, V
OLB/DE: Chandler Jones, Syracuse - I
OLB/DE: Shea McClellin, Boise State - APD, MC
OLB/DE: Nick Perry, USC - APD, V
OLB/DE: Courtney Upshaw - I, MC, APD
OLB/DE: Kyle Wilber, Wake Forest - APD, MC
There are others but we were clearly looking at first or early round pass rushers.
S: Markelle Martin, Oklahoma State - V
S: Harrison Smith, Notre Dame - MC
S: Brandon Taylor, LSU - APD, PW (JMc)
Interestingly whilst we looked at some LB's, only Luke Kuechly qualifies as being similar to Hightower. So Hightower probably got the Saban seal of approval which reduced the need to look around (hence my suggestion of Jesse Williams).
2011
QB's
QB: Andy Dalton, TCU - PW
QB: Colin Kaepernick, Nevada - I
QB: Jake Locker, Washington - V
QB: Ryan Mallet, Arkansas - V
RB's
RB: Mario Fannin, Auburn - RI
RB: Alex Green, Hawaii - I
RB: Kendall Hunter, Oklahoma State - PW, V
RB: Taiwan Jones, Eastern Washington - APD
RB: Mikel Leshoure, Illinois - V
RB: Derrick Locke, Kentucky - I, PW
RB: DeMarco Murray, Oklahoma - I
RB: Bilal Powell, Louisville - MC (either PW, or V not yet confirmed)
RB: Jacquizz Rodgers, Oregon State - MC
RB: Da'Rel Scott, Maryland - PW
RB: Daniel Thomas, Kansas State - PW
RB: Jordan Todman, Conneticut - C (IF), V
RB: Ryan Williams, Virginia Tech - PW (IF)
OT's
OT: Joseph Barksdale, Louisiana - I
OT: Gabe Carimi, Wisconsin - I
OT: James Carpenter, Alabama - APD, C (DS)
OT: Anthony Castonzo, Boston - APD (DS)
OT: Marcus Gilbert, Florida - I
OT: Chris Hairston, Clemson - PW
OT: Rich Lapham, Boston - RI
OT: Tyron Smith, Southern California - APD, V
OT: Nate Solder, Colorado - V
OT: Danny Watkins, Baylor - I
2010:
CB's
Kyle Wilson
Kareem Jackson
Devin McCourty
Chris Cook
Javier Arenas
TE
Jermaine Gresham
Jimmy Graham
Rob Gronkowski
Dennis Pitta
Tony Moeaki
Aaron Hernandez
and interestingly - Jake Ballard
We also looked at most of Cunningham's rivals and a good number of MLB's.
The point is this: in the last three years, the Patriots have had contacts with most of the immediate rivals for players we've subsequently drafted with the exception of Hightower. So far, the only DT's we've been linked to are UDFA types. So, unless there's someone specific, the recent track record suggests not getting up your hopes for a DT.