2014 US Senate Election

there has been NO decision if Lautenberg will retire or not.

You are assuming that he will retire because of his age.

And Booker said will not challenge if Lautenberg stays on.

Levin-MI is a decade younger than Lautenberg-NJ.
Levin-MI running again means Peters-D runs for Governor against Snyder-R who is likely to be a one Termer.
Johnson-SD had a stroke 5 years ago has a top tier Republican opponent-ex Governor Rounds-R but Johnson-D survived a tough race against Thune-R in 2002.
Regarding Lautenberg-D
The question is not whether or not he wants to leave the US Senate in a body bag but does he want a Democrat or a Republican to succeed him.
If a Democrat wins the 2013 NJ Governors race which is unlikely to occur because of Christies popularity-then Lautenberg would run again in 2014. Because Christie-R is favored to win in 2013, Lautenberg-D successor if he were to run again will be a Republican unless Christie appoints Jim Florio or Jim McGreevey as the interim appointee-which is unlikely to happen. Christie will appoint a Republican to succeed Lautenberg.

Depending what Governor Kitzhaber does, he may take a shot at running for governor.

Democratic Held US Senate Seats up for grabs in 2014.
Solid Democratic
DE(Coons-D) GOP challenger will be some unknown wackjob. 35D
IL(Durbin-D) GOP challenger will be Walsh-R or some unknown wackjob. 36D
RI(Reed-D) GOP challenger will be some unknown wackjob. 37D
Likely/Solid Democratic.
HI(Schatz-D) Lingle-R,Aiona-R,or Djou-R will recieve less than 40% of the popular vote in the November General. 38D
MA(Markey-D) Assuming Markey-D faced and defeated Brown-R in the 2013 Special or defeated Weld-R/Baker-R/Tisei-R. Brown-R will not be the GOP nominee. 39D
Likely Democratic
MT(Baucus-D) GOP challenger will be some unknown wackjob. 40D
NJ(Lautenberg-D or Booker-D) I'd like to see Runyan-R or Garrett-R seek the GOP nomination. 41D
NM(Udall-D) GOP challenger will be John Sanchez-R or some unknown wackjob. 42D
OR(Merkley-D) GOP challenger will be some unknown wackjob.-43D
VA(Warner-D) GOP challenger will be McDonnell-R or some unknown wackjob 44D
Lean/Likely Democratic.
CO(Udall-D) Norton-R or Coffman-R. 45D
IA(Harkin-D) King-R or Latham-R 46D
MI(Levin-D or Peters-D). If Levin-D is the Democratic nominee, he will face some unknown wackjob. if Peters-D is the Democratic nominee-Republican nominee will be Engler-R or Hoekstra-R. I like to see Lynn Rivers-whose Congressional District got eliminated in 2002-forcing her to run in Dingell's district make a comeback. An Engler-R vs Rivers-D matchup will be like the 2012 WI US Senate Race-Baldwin-D vs Thompson-R, A popular former Governor-R getting his butt kicked by the most liberal Democratic US House Member. 47D
MN(Franken-D) Bachmann-R 48D
NH(Shaheen-D) Sununu-R,LaMontagne-R,Guinta-R or Bass-R will recieve less than 45% of the popular vote in the November General Election. 49D
Lean Democratic
AK(Begich-D) Treadwell-R, Begich-D is personally popular in the state despite its strong GOP lean. 50D
AR(Pryor-D) Darr-R, Pryor-D is personally popular in the state despite its strong GOP lean. 51D
LA(Landrieu-D) Cassidy-R or Landry-R represent the Akin wing of the Republican Party. 52D
NC(Hagan-D) Thillis-R, State is turning purple, Republicans are being more Rightwing. 53D
Tossup Democratic.
SD(Johnson-D or Herseth Sandlin-D) Johnson-D defeats Rounds-R, Herseth-D loses to Rounds-R by a single digit margin. 54D
Lean Republican Takeover.
WV(OPEN) Senator Elect Shelly Moore Capito-R. 32R

AL(Sessions-R) Jim Folsom-D
GA(Chambliss-R) Roy Barnes-D
ID(Risch-R) Walter Minnick-D
KS(Roberts-R) Kathleen Sebelius-D
KY(McConnell-R) Ben Chandler-D
ME(Collins-R) John Baldacci-D
MS(Cochran-R) Mike Moore-D
NE(Johanns-R)
OK(Inhofe-R) Brad Henry-D
SC(Graham-R)Jim Hodges-D
SC(Scott-R) Vincent Sheehan-D
TN(Alexander-R) Phil Bredensen-D
TX(Cornyn-R) Julian Castro-D.
WY(Enzi-R) Dave Freudenthal-D

a lot of conservative pro-gun states with Dem incumbents.

Harry Reid is Majority Leader and Pat Leahy chairs the Senate Judiciary Committee.