Also note that you can vote for the Overheard quotes. Thumbs Up, Thumbs Down, and WTF? need no explanation. But I had to Google "Alsome," which turns out to be the way the REALLY cool folks say and spell "awesome." (Well, spell it anyway. I'm not sure the two words are pronounced very differently. Hey, Linguist Guy, whaddya think?)
I think some people might pronounce it with an [l] or more likely one of the darker L's--either a velarized alveolar lateral approximant [ɫ] or the velar lateral approximant [ʟ].
English commonly uses the dark-l in a coda position and the light-l in an onset. The usual transcription of the dark-l indicates that velarization is a secondary articulation. [l] is an alveolar consonant and is articulated with the tip of the tongue against the alveolar ridge. Velarization means that in a secondary articulation the back of the tongue is also raised giving it a 'dark' sound. Compare the first and second L in little. Or the L in light with the L in call. The difference is indicated by the tilde that runs through the symbol [ɫ]. [liɾɫ̩] [lait] [kaɫ]
The velar lateral approximant is primarily velar and so the raised back of the tongue (the dorsum, think the dorsal fin on the back of a fish) is the primary articulation. The tip of the tongue isn't the main indicator of place. Although this is not a standard phone in English it does occur in some accents and some pronunciations as when a coda L is left markedly open. In fast speech the L in a phrase like 'all of them' might remain completely dorsal without any alveolar articulation.
Consider how close to 'awvem' that can sound. Now consider that some dialects will pronounce L's like W's. Ever heard someone say 'widow' instead of 'little'? It's a common early pronunciation among children because the sounds are similar acoustically. I know one child who pronounced 'flower' like 'wallow'--a complete reversal of the [l] and [w] approximants. Tho this might have been metathesis instead of an articulation issue.
Just earlier today I heard 'saw' pronounced before a vowel like 'sawl'. It was overheard only once so I'm not sure if it was a velar lateral or a velarized alveolar lateral, but it was definitely an approximant. I've heard it before. I asked a friend if she hears this a lot around here in Nebraska. She rolled her eyes and gave an exasperated "Ugh. Yes."
Before a vowel it's very much like I sawr 'im leaving which we would expect to hear in some northeastern American dialects. The approximant makes a nice onset for the following syllable.
I imagine also that to those who are used to hearing [ɑ] in 'awesome' the northeastern closing and rounding and raising to [ɔ] could be interpreted the same as a velar approximation.
Whatever the process there are plenty of likely explanations for the awesome/alsome alternation.