Yes, they're cumulative, mostly adding/refreshing drivers for new and existing hardware. Occasionally like for some most recent kernels they ripped out bits that hardly are used, like say to exaggerate, support for PC-XT hardware. They did and that took off quite a few megabytes. [Each kernel takes about 275MB diskspace, but the latest 3.16 LTS is up to 280 now]. Occasionally see a list when running sudo apt-get upgrade summoning to run 'apt-get autoremove' to ditch old kernels. The last 2 wiped took 557MB].

As it is, Linux once stable runs and runs, so if there's no 'must have' features, no reason to force an upgrade to a next major. Forcing kernel upgrades beyond the supported level could break things.

There's already a 4.n LTS, so hope is indeed in the 14.04 pathway, but https://wiki.ubuntu.com/Kernel/LTSEnablementStack says it will be 3.19 for 14.4.3 (next 14.04 kernel update) with kernels for 14.04.4 and 14.04.5 in TBO (To be Announced).

More DIY fun, how to convince your system to log out at an interval convenient to you [or you insist on for users who've been idle for nn minutes: http://www.cyberciti.biz/faq/linux-tmout-shell-autologout-variable/

This article about assembly code cleanup in the kernel http://www.itrunsonlinux.com/desktopos/linux-kernel-code-cleanup/ I saw after reading that the subject final 4.1 was actually released...https://lkml.org/lkml/2015/6/22/8 which is an LTS release!

Don't know [but Google is everyone's friend to tell you ;]. Certainly got the 3.16 to update automatically into my Thar 14.04LTS. 3.16 then updates from the Utopic RPMs. Not so sure if shoeing in 4.10 [4.2 dev now kick off], does anything at all for your hardware in terms of battery extension. Here's a feature summary: http://www.omgubuntu.co.uk/2015/06/linux-4-1-kernel-new-features

Kernel 4.2 has a bunch of scheduler improvements. https://www.phoronix.com/scan.php?page=news_i...ux-4.2-Scheduler-Upgrades . Lots of news on Kernel 4.2 at Phoronix: https://www.google.com/cse?cx=partner-pub-025...rnel%204.2&gsc.page=1 with a forward look in this article: http://www.phoronix.com/scan.php?page=news_it...linux-4.2-features-coming

Interesting is that 4.1 EXT4 FS now has file encryption [courtesy of a Google contribution who put it into Android M for starters]... ultra secure https://www.phoronix.com/scan.php?page=news_item&px=EXT4-Changes-Linux-4.1 . As many know, without and having physical access makes it a piece of cake to get access to partitions and file access [which is why critical files themselves should be saved with proper passwords.] Lots of times I thought to have lost the access [had backups though], and got it back by simply reassigning file ownership on Windows.

The article holds this most heads-up note "The design and implementation might end up getting shared too with the new F2FS Flash-Friendly File-System." Is this going to help SSD's?

for the Minties amongst you: http://www.eweek.com/enterprise-apps/slidesho...s-desktop-experience.html

The link pretty much tells what's it about :D