With second base becoming the position without a long-term solution, let's look at current second baseman Ronnie Belliard's similars to see if signing him to a long-term contract is a good idea. Belliard will turn 31 on April 7, and is a free agent at the end of this upcoming season. The numbers in parenthesis are the player's similiarity score, with 1000 being a perfect match for Belliard's career through age 30.
(1) 2B Mike Lansing (960)
Lansing was a product of Wichita State (who apparently also has a basketball team), and was drafted by an independent baseball team in 1990 (the loophole that allowed it has since been closed). The Montreal Expos purchased his contract in 1991, and he broke into the majors in 1993. For the next five seasons, he posted very solid numbers for the Expos. His best season came in 1997, when he was 29 years old.
The Expos dealt him to the Colorado Rockies after the 1997 season, getting three prospects in return. One of those prospects was current Indians starter Jake Westbrook. After Lansing left Montreal, he was pretty much finished. This comp is a definite "no" for keeping Belliard around.
(2) 2B Todd Walker (947)
Walker is two years older than Belliard, and is still a good hitter. Walker's problem is that his defense has never been that great, which has decreased his overall value. He's consistantly posted negative FRAAs at second base, which may lead to him becoming a first baseman or a part-time player. The Cubs may trade him before Opening Day.
Why is Walker relevant? Before 2005, Belliard's defensive numbers mirrored Walker's; he posted negative FRAAs each of the previous three seasons. Ronnie may be fooling BPro's fielding metrics with his positioning, and I think he's one of the best in baseball at turning a double play. Still, it's something to keep an eye on as the season progresses.
(3) 2B Damion Easley (945)
Another near-contemporary. Easley started his career with the Angels, and has lasted as long he has because of his defense. His best all-around seasons came in his late 20s. The Detroit Tigers signed him to a long-term contract in 1998 and came to regret it. In recent seasons, he's become a utility infielder.
(4) 2B Robby Thompson (939)
A solid player with the Giants in the late 1980s/early 1990s. He was an excellent fielder (he won a Gold Glove in 1993), and during his peak, a very good hitter. From 1988-1993, he posted EQAs of .276, .276, .258, .295, .278, and .305.
As to the question at hand, Thompson was a part-time player after his Age 31 season, and out of baseball by age 34. So far, the concensus is "no" for keeping Belliard around.
(5) SS/3B/OF Hubie Brooks (937)
Brooks was an offense-first infielder/outfielder for the Mets and Expos during his prime. He started out his career as a third baseman with the New York Mets. He was dealt to the Expos in the Gary Carter trade, and Montreal moved him to shortstop (Tim Wallach was already at third). He continued to put up good offensive numbers, but his defense was less than stellar. Finally, the Expos moved him to the outfield in 1988, where he remained for the rest of his career.
(6) 2B Bret Boone (934)
This comp seems a bit off base, but if you compare the two through age 30, it doesn't seem quite as ludicrous. Boone was known as a good defensive second baseman with a pretty good offensive game as well. It really wasn't until he returned to Seattle in 2001 that he hit more than 30 homers in a season.
I'd place the odds of Belliard going down the Boone career path as very remote.
(7) 2B Bill Doran (928)Doran was a stalwart for the Houston Astros in the 1980s. He didn't hit for a lot of power in the Astrodome (not many did), but had good on-base skills and was a decent base-stealer. His defense was generally above-average as well. When did Doran start losing it? After he turned 30; he put up good numbers in part-time duty with Cincinnati and Houston from 1990 to 1992, but his power and speed was basically gone by then.
(8) 2B Tony Bernazard (925)Bernazard came to the Indians from Seattle in December 1983. He spent three full seasons in Cleveland, his best being 1986, at the age of 29. The Indians dealt him to Oakland in 1987, and that was pretty much a career for Tony.
(9) 2B Jerry Priddy (922)Priddy played in second base in the 1940s and 1950s for four AL teams; his best years came with St. Louis. His last full-time season was in 1951 with Detroit at age 31.
(10) 2B Aaron Ward (922)Ward broke into the big leagues at age 20 with the Yankees; his first full season came in 1920 at the age 23. He was the Yankees' regular second baseman for the next six years. He lost his starting job in 1926, and was traded to the White Sox that offseason. He posted solid numbers in 1927, but that was his swan song; he got nine at-bats with the Indians in 1928, but that was it for him.
Most of the players listed above are cautionary tales; only Bret Boone had real success as a second baseman after age 30. Belliard falls outside the scope of a core player, and although there isn't an obvious succesor in the organization, it would be a mistake to sign him to a long-term contract.